elbdogs is correct - there is no 3-button M6P as far as I know, only a 1-button with volume slider. I still have at least two M6s (might still have my 1st-gen one somewhere). Use them while running and with other dangerous (for IEMs) activities. Sound-wise they are no VSD1S but for $20 I can't say I feel they are lacking anything. I've never found the bass quantity on them lacking but the fit can be a little tricky at first. I think the stock tips have improved over the years - the bi-flanges that came with my newest set actually fit me pretty well.
The E10M does sound better but may not be as durable in the long run. It has a true 3-button control though. Ditto on the Ultimate Ears 500vi - the other sub $40 3-button set I would recommend for sound quality over the M6P, but not for construction.
Thanks! I went with the M6P eventually as I would be using them right now for working out and such and if I require good IEMs for other use, I'll stretch my budget and get something that has even better quality than both E10M and M6P when I'll be back in Europe. Might aswell take the opportunity to order Meelectronics as I'm in the States right now!
I'll hopefully be happy with them even as I use them daily on commutes as such, we'll see! They'll probably be a (big?) improvement over the stock Apple Earbuds I was using daily.