You folks convinced me on the merits of getting the ETS EC 125 as my first Festool sander along with the 202458 150mm pad (which seemed like a good general purpose choice for wood). My understanding is that Festool's current reason not to recommend this setup is that the brake may not work, but all of the people here who have tried it haven't had a problem with the brake not working.

Now that I have the sander I'd like to confirm that the brake works on my specific sander. Could somebody please help me understand how to do that?

The pad should stop rotating in less than a second after you shut it off, mine stops within 1/2 a second.

That actually might be the case on those new ec sanders, but on the rotex, that rubber ring was referred to as "the pad brake". (and yes, it's also essential for the dustextraction)

Check out this vid :

If the pad brake, the rubber ring that touches the pad, doesn't work, you'll notice the pad will speed up uncontrollably fast. It is a huge difference. I have replaced a few pad brakes on a few sanders by now, and what gives it away is that the pad spins like it wants to take off into orbit.

Thanks everybody. So the good news is that I tested the 150mm pad and it definitely stops very quickly when turned off (indistinguishable from the 125 pad). So I think everything is good there.

The one interesting thing I noticed is that during my tests (turning the sander on with the pad flat facing directly upward so I could see it) the 150mm pad spun at around 70 RPM (I counted 12-13 rotations in 10 seconds) but the 125mm pad turns much less quickly, varying between half that and no spinning at all (seen by the dust collection holes remaining in place making little 3mm circles without rotating the pad). Is that normal? The back of the 120mm pad did come with a good amount of grease on it in the area where it contacts the brake pad, not sure if that's relevant.

I did take a look and it certainly looks like the brake pad is contacting the 150mm pad. Comparing it to the 125mm pad I can't see any difference in how it contacts and on the 150mm pad I do see a narrow band of grease transferred from the brake pad.

Thanks for all the helpful input, everything is probably fine but I want to discover any issues within the 30 day return period so I can return it for the ETS EC 150 if needed.

My 6” sandpaper came so I was able to test out both pads side by side and they both work great (though the larger pad works noticeably faster as expected )! After using both pads a bit they spin very similarly so I think the difference I was seeing was just a bit of extra initial friction or the thick layer of grease on the smaller pad.

Thanks for all the assistance folks.

The one interesting thing I noticed is that during my tests (turning the sander on with the pad flat facing directly upward so I could see it) the 150mm pad spun at around 70 RPM (I counted 12-13 rotations in 10 seconds) but the 125mm pad turns much less quickly, varying between half that and no spinning at all.

I have the 125/3 with the 6" pad and I am ordering the ETS EC150/5. I think putting the 6" pad on the 5" Machine is a bad idea because the machine is not balanced right when you do that. You can feel it, and the fact the 150 mm disc spins a lot faster with the wrong disc is an indication of that.