Brian,
I've been playing DGX-1's in the Ping S59 for a couple of years now. A couple of buddies of mine have talked about the Project X's lately but I never paid it much mind. I always hated the Rifle shafts (couldn't stand the feel). Well, I start to notice that everyone on tour seems to be playing the Project X. Seems like you can't get a follow thru picture on tv w/out seeing that blue label! (Was that Tigre I saw using them?).
Anyway, I'm playing last Sunday and one of the guys in our group is warming up and he's got the 6.0 PX's (I hear most pro's are using the 6.5). I'm already warmed up but grab his TM 6-i and hit about 5 shots. Let's just say that I'll be ordering a new set of irons with that same shaft this winter. I could not believe how STABLE and SOLID they felt to say nothing about their claims that the ball gets "up" quicker and then flattens out.... that really seems to be the case! Sort of hard to describe, but the feel was VERY different from the DG (and the Rifle's that I remember) and I always thought the DG was the "only" iron shaft going. Not sure if they're for everyone, but I would think that most "players" would notice a positive difference.