Shark Stratos Cordless Review

The Shark Stratos IZ420EUT upright hoover has a huge suction head with two rotating brushes, but it’s also one of the first models from the brand to feature an automatic power adjustment mode.

Less well known in France than the inevitable Dyson, Rowenta or Electrolux, American manufacturer Shark is nevertheless showing a ferocious appetite in the upright hoover market. The Stratos IZ420EUT is its latest model. Priced at €399.99, it stands out from the competition thanks to a massive suction head, not full of teeth, but full of rotating brushes; in fact, there are two of them to choose from. The first resembles the soft or “fluffy” brushes popularised by Dyson, while the second, more conventional, uses hard bristles and rubber blades to beat textiles and extract dust (PowerFins system).

To drive these brushes and supply energy to the motor, the Stratos is equipped with a Li-ion battery that is supposed to give it 60 minutes of autonomy, which should be more than enough to fill the 0.77-litre waste bin. The bin contains the monocyclonic filtration system that separates the air from the dust. Like other upright hoovers before it, it has a particle counter to tell the user how clean the floor is, and to modulate suction power according to the amount of waste collected. In a nutshell, the Stratos IZ420EUT is solidly equipped to win the top spots in our comparison.

Ease of use
The Shark Stratos IZ420EUT is a stick hoover. The heavy components – the motor, filtration system and waste bin – are located close to the user’s wrist, so he or she can turn the machine in any direction – with or without the suction tube connected – to reach the most inaccessible nooks and crannies. In handheld vacuum mode, it weighs just 1.66 kg, so you can handle it without too much effort. However, when you attach the suction tube and head, the scale goes into overdrive, weighing in at 4.01 kg.

shark stratos cordless

Admittedly, most of the weight is borne by the floor, but it doesn’t take long to get tired of pushing and pulling the Stratos IZ420EUT, even though the rotating brushes tend to ease the movement, towards the front at any rate. Good point: the head is flexible enough to take the tightest bends without skidding. What’s more, the suction tube has an articulation system, similar to that of the Rowenta X-Force Flex 8.60 Animal Kit RH9679WO. At the touch of a button, the hose unbends to make it easier to get under furniture. This makes for greater agility, but there’s another advantage to this feature. By completely folding up the suction tube, the Stratos IZ420EUT can be stored in a compact position, with no need for a base to be placed on the floor or fixed to the wall – a real plus for small spaces or for those who don’t want to take the drill out to install a wall base.

Once folded, the Stratos doesn’t take up much space and stands up on its own.

But let’s get back to the main reason why the Stratos IZ420EUT weighs so much: its massive suction head. In fact, it weighs 1.86 kg on its own, as it houses two rotating brushes and the motor needed to turn them.

The Stratos does have a big head.

But that’s not all, as Shark has also fitted it with a front LED system to light up dark floors or the underside of furniture, and a floor cleanliness indicator. The latter takes the form of a light bar on the back of the head. The longer the bar, the dirtier the floor. If all goes well, the size of the bar decreases as the floor is vacuumed, and you change zones when the bar has almost disappeared.

The luminous bar, almost extinguished, indicates that the area has not yet been completely dusted.

Two sensors near the air intake of the main body analyse the level of dust in the air sucked in to determine whether the floor is clean. The system works quite well, and you get the hang of it very quickly. The results are also used by the Stratos IZ420EUT to modulate the suction power of the automatic mode according to immediate needs (autoIQ system). Once again, everything seems to work perfectly and you can clearly feel the motor speed decreasing when you stay in one place for a long time and less and less dust (theoretically) passes in front of the famous sensors.

A control panel that’s easy to master.

This automatic mode is not the only one available, and users can choose between it, an eco mode and a boost mode. To switch from one to the other, all you have to do is press the button adorned with a fan that fits perfectly under your thumb. Of course, the Stratos IZ420EUT must first be switched on. The rest of the control panel consists of an electronic display that indicates the remaining battery life using a percentage. This method is more meaningful than a simple trio of LEDs, but it’s also less accurate than a second-by-second estimate like that offered by the Dyson V11, among others.

Shark supplies an extra battery.

Shark is quite generous with its accessories. As well as the hoover itself, the tube and the suction head, the box contains a classic brush, a contoured brush for tight spaces such as radiators, a mini electrobrush and a long nozzle. It’s worth noting that our version also comes with a battery charger that can take two batteries at a time, which is rare enough to be worth mentioning.

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Vacuuming
Whatever the surface it’s used on, the Shark Stratos IZ420EUT demonstrates its excellent qualities thanks to its dual brush.

On long pile carpets, you can expect to pick up 100% of the detritus in two minutes, even without switching on the boost mode. Incidentally, this mode tends to vacuum a little too hard and, in certain conditions, it can even swallow the edges of the carpet, so be careful to choose the right suction power to avoid making the job harder.

Vacuuming performance is also excellent on fine carpets, again in both normal and boost modes. In normal mode, the efficiency rate reaches 97% in 30 seconds. In the second mode, it rises to 98% in the same time. In one minute, the floor is immaculate.

Finally, on hard floors, the Shark Stratos IZ420EUT swallows 98% of waste in thirty seconds, in automatic or boost mode. Once again, the result is impeccable after just one minute.

Maintenance
Emptying the Shark Stratos IZ420EUT’s waste bin is as simple as pressing a button on the collector. The hinged bottom opens and drops the waste into the bin. Some systems are more sophisticated, but the one used by Shark works very well.

The bare filtration system.

The cyclonic filtration system isn’t perfect. We made the Stratos IZ420EUT swallow 20 grams of cocoa powder before weighing the foam and HEPA filters with a precision balance. The former weighed 0.427 grams and the latter 0.097 grams. You’ll need to remember to clean them regularly enough to avoid them becoming saturated with fine dust, which would ultimately impair suction performance. Fortunately, it’s relatively easy to access the various filters, but it’s impossible to dismantle everything, and dust loves nothing more than to lodge itself in out-of-reach spaces.

The vacuum head disassembled.

The suction head has a comb system to prevent long hairs from getting tangled up in the hard brush – a rather effective system, by the way. You can always remove a cover under the brush to free it up if you need to. However, you’ll need to use a tool (coin or spoon handle) to release the catches that hold everything in place. These catches do not exist to lock the soft brush in place, so all you have to do is manipulate a pull cord to remove it from its housing. Putting it back in place is no more complicated.

Autonomy
The battery life of the Stratos IZ420EUT is nothing exceptional.

In automatic mode, it can vacuum for 47 minutes without interruption. Of course, this time may vary depending on how dirty the rooms are, as the power of the upright hoover changes according to the amount of dust it collects.

In boost mode, autonomy is drastically reduced to just 13 min 20 sec.

A full recharge takes 3 hours 30 minutes.

Noise
Like the autonomy, the noise level varies when using the automatic mode. According to our sound level meter, it varies between 59 and 64 dB(A), depending of course on the power used.

In boost mode, the display of our measuring instrument no longer varies and indicates 70 dB(A).

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Strengths
Comfortable on all surfaces.
Easy to store.
Relevant and effective autoIQ system.
Weak points
Heavy in floor vacuum mode.
Filtration could be improved.
Some nooks and crannies in the collector impossible to clean properly.
Conclusion
Overall rating

How does the rating work?

Even if you need good biceps to handle it, the Shark Stratos IZ420EUT has plenty of bite on all surfaces. We liked the little extras it comes with, such as the well thought-out autoIQ system and the articulated suction tube, which makes dusting under furniture effortless, as well as allowing you to store the hoover without it taking up too much space. Unfortunately, its cyclonic filtration system isn’t efficient enough to allow the Stratos IZ420EUT to take pride of place in our comparison.