Am sure that model, the newest one, is the one that has the flaws (like the spring guide snapping since it's pot metal), and the 2005 I'm sure has flaws as well. What I've seen among my digging (and experience with my own) is the pre-2005 models are the most robust.
Give this a read:
http://www.airsoftretreat.com/forums...?topic=46095.0