[Deschodt]

Like people pointed out 2008 to 2010 is an odd range... Either you get an 06-08 cheap and risk the IMS issue (a problem as you cannot replace it w/o splitting the case), or you get a more expensive 09+ and sleep easier, regardless of actual % failure, and recoup that at resale time.
I actually prefer the looks of the original one's tail, but I'd buy an 09 and above for peace of mind. Actually I believe the sweet spot is the 981. Great cars, more handling than power, especially in a base version - mine required a water pump at 45K mi, and an inside door handle repair (by me), oh and new radio buttons (turned to goo) - that is pretty much all - not the end of the world. Only thing I'd say is on a base Cayman I'd go for a stick instead to enjoy wringing the crap out of it, it's a sweet gearbox.