Hmm, that's weird, I have had my 400 series XPR for several years now and it's been perfectly fine electrically and mechanically. I usually use the flex shaft, and sometimes use the blade sharpening attachment (which really just guides the grinding wheel). It has been quite useful, though I probably only use it once a week to once a month, as I don't have much that needs dremeling.

Brijar!!!

Yep, my 395 will get hot under continuous use - I keep a pr of mechanics gloves around - started doing that for soldering where the wire I was holding would get hot before the solder set. Use them and I'm aware dremel is warm, but not much more. Used to be I'd do like BrianG and just take a half hr break when it got really warm.

Haven't have to clean the switch - if I just run the switch back and forth with it off/unplugged a few times every so often that seems to keeps it clean. Been happy with it for more than 3 yrs and wouldn't want to be without.