Mirka deros or Mafell eva150e???

As you've undoubtedly realised from your collective DEROS purchases, it comes bundled with an additional/accessory counterweight for the sander's main shaft. The idea is to exchange or add the additional counterweight to compensate for the different offset centrifugal inertia characteristics of the 2 bundled platen sizes.  As with the 3 different DEOS platen sizes too I believe:  they can be purchased from the relevant parts diagrams.

Unless you actually use said counterweight, of course you'll experience undue vibration. Some trial & error may be required to achieve the smoothest results. Those clever Scandi design boffins have gone to great lengths to both monitor & counter vibration with their sanders. As a last resort you could actually read the tool's manual. Haven't actually done so myself, but I'm reliably informed that they occasionally contain useful information!

I have 4 Mirkas: 5 & 8mm DEROS & small & large(ish) DEOS, plus an additional Delmeq large delta clone of the DEOS, now available in genuine Mirka livery. This collection is simply superior to any other equivalents that I've ever used. I have already disposed of all but 1 of my 8 odd Festo/ol sanders as a consequence. The Mirka, Metabo, Rupes, Indasa, Sumake & Carsystem clones are really that good in my opinion. Actually gave away the larger DEOS as its long thin platen is actually yet another abrasive size (70 x 200??) that I don't really want to stock. It's apparently more of a plasterer's/painter's sander size that I don't actually readily require.

I have 2 caveats however: firstly, I've never been a huge fan of Plug-It type power cables. It introduces yet another potentially problematic connector into what should be a pure, uncluttered & uncontaminated electron flow. Although I've never yet actually experienced any dodgy connections from my own Mirkas, I have had problems in the past from Festool's equivalent. I prefer to keep all relevant sanders permanently attached to the vac through a simple power board & simply exchange vac hoses, or even use a vac hose Y-adapter instead. Less (or in my case no) plug/unplug cycles will hopefully preserve a nice clean uncontaminated connection. There's plenty of anecdotal evidence on the interweb of user's difficulties with dodgy Mirka power cable connections.  Both the Mirka & Metabo use proprietory Plug-Its; AFAIK the others (def. the Delmeq) don't.

Secondly, whilst I do particularly like the top on/off & variable speed paddle on the Mirka & its clones, I still sometimes inadvertently set it down inverted (switching it on) when all I want to do is to exchange abrasives. The fix? Make a simple plywood template/abrasive garage preloaded with gritside-down abrasives. Tear off the used one & press down on the garage for a new abrasive correctly aligned & installed.  I never use the paddle to vary the speed:  it's nuts to try to hold the paddle down part-way!  Use the speed switches instead, & the paddle as an on/off control.

I also sometimes get a bit tired having to hold the paddle down constantly. As a CTS sufferer, I like to change my grip often to reduce strain & vibration on similar muscle groups in my hands & susceptible right wrist's carpal tunnel. I sometimes change hands too. In comparison to other EC sanders (Festool's EC sanders for example are 20% heavier, and the Rotex 150 over twice the weight, albeit slightly faster in Rotary action!) the Mirka & clones are both featherweights & ergonomic delights. To keep the paddle depressed, a short length of insulation tape is a useful quick-release remedy that allows me to vary my grip widely.

As you can tell, I'm a bit of a fanboy. Not without reason 'though I might add. To me the Mirka collection makes most, if not all other sanders that I've ever owned or used seem rather primitive & crude in comparison. At < 1kg each, it just makes sense for extended sanding sessions. I'm still keeping my monster Holz Her/Festo Belt/Frame sander, & little Bosch GDA delta and a couple of 80mm Metabo SXE400s, but only because they're (now) rarely used specialist sanders for occasional small or inaccessible jobs (mouldings, concavities & other fiddly bits) that are't within the Mirka's gambit.

I only have the 4 Mirkas (now only 3) & a single Delmeq, so can't really comment authoratatively.  Suffice it to say that key parts (platens, padsavers, intermediate pads, possibly motors & superstructural components too & of course abrasives) will be interchangeable.

To the poster concerned with abrasive life, I can only comment on my own experience.  HD Ace abrasives, with high ceramic content, are also available in 40 & 60 grits, & have adequate performance & life.  Paint stripping is extremely hard on any tool &/or abrasive. Coarser grits will both last longer & (obviously) abrade faster than finer ones in stripping multiple paint layers.  Their net/mesh structure will also be much less prone to clogging from heat buildup & "plastication" or "liquefaction" of paint residues, always a problem for more solid paper & cloth backed abrasives.  Irrespective of hardware or software choice, it's simple common sense to exchange the abrasive as soon as its performance drops.  No abrasive lasts well paint stripping.

As the Mirka & Abranet families & their imitators & clones are particularly suited (& used as such) in the automotive paint refinishing industry, and by professional painters & plasterers, I'd suggest that you'd probably be extremely hard-pressed to find better.  Any issues of abrasive longevity may actually be more about the substrate (i.e. paint layer's) hardness or abrasiveness than any abrasive inadequacy.

Appropriate choice is the key: size, type and grit.  For instance, I don't use Abranet Ace belts, simply because a belt sander's extraction aerodynamics aren't predicated around mesh abrasives.  However, multihole platens (i.e. Mirka et. al.), are purposefully designed for mesh.  Sanding belts from Flexovit are available down to 24 grit, and equivalent cloth-backed discs for grinders down to a finger-shredding 16 g, and paper & cloth multihole discs in 125 & 150 mm diameters down to 24 g from at least some manufacturers. Whilst purposefully suited and designed for mesh abrasives, there's really no reason why Mirkas & their clones can't be used with appropriately hole-punched conventional abrasives either.  I often use cheaper paper 40g rectangles, deltas & discs with my own tools. I also use smaller 75mm rounds & 93mm delta mesh abrasives in my small Bosch & Metabo sanders too, with pleasing results.

I can second that.
After I was impressed by the lack of vibration from the UVA (rectangle base), I felt the need for the EVA.
I mainly sand wood and oiled wood in conjunction with Abranet at full speed. I found they don’t behave as well with Granat paper. I think there is a more direct coupling due to shorter Velcro hair and lack of protection pad.

If held at the handle, there is sometimes absolutely no vibration. Vibration in the vacuum hose is greater than at the handle. Some vibration seems to be conducted back via the hose through the power cord.
It really is impressive. I’d like to compare it to the ETS EC and the Deros (or one of its siblings).

Iban, do you have 2.5 or 5 mm stroke Deros (or even 8)?
Mirka states 2.4 m/s^2 for the 2.5 mm and 3.4 for the 5 mm stroke.
The GEX only has 2 mm stroke. These numbers come with a relativly high uncertainty of typically 1.5 m/s^2.

Since Mirka has an app to have a look at the recorded vibration, maybe they are very conservative with theyre numbers? I'm not familiar with how this is measured but I'm shore it is somehow standardized, possibly with a little bit of room for interpretation/variation.

Mafell yust states "less than 2.5 m/s^2" for all of the sanders.
I have a Mirka DEOS 353CV stated as 2.6 m/s^2 and it feels more than both the Mafells, still very good.

Interestingly Festool states 4.8 m/s^2 for the ETS EC 150 both 3 and 5 mm.

Deros 5mm stroke and the bosch is 4mm orbit diameter, not 2mm.
I didn't work with either for hours but the Mirka looks kilometres ahead of the of bosch