This is not trying to hate on MS, but the first and foremost thing I noticed with achievements, were the many online achievements they have. Gears of war, Perfect Dark Zero, crackdown has some as well(doesn't it?). This was before I even had a PS3. I realized this was just a way for MS to promote their XBL gold and nothing else.
So I hated achievements. Fast forward one year, I got a PS3, I was happy it didn't have achievements, and I was proud of it. And then trophies arrived >.>
But I realized later that it was a move by Sony because fans were asking just like in-game XMB(which is awesome) so I understand.
All these achievements and trophy arguments are just BS, and now that I play PS3 more, I am accustomed to the trophies more but achievements have auto-synch which you guys conviniently forget. No need to press sychronize every time you shut your PS3 down after a session. Of course, the platinum trophy cancels it out imo because that's an awesome implementation, and I have one in one of my favorite AC 2!