I was fitted the 712 CB
the fitter suggested DG R300 +0,25 inc and 2degrees up. My Swingspeed is 86 Mph and smachfactor was 1.4
Is this any good? or should I try Project X 5.5?
At this moment I play 710 AP2 with DG R300.
That is a good smashfactor (out of 1.5) and assuming that is your club head speed with a driver, that's a good flex. Since the Club Fitter was able to analyze your ball flight and ball striking, I would say stick with his suggestions. You can always consult other Club Fitters if you feel the fitting didn't go well, but these numbers are showing any red flags of an incorrect fitting.
Thanks, but the swingspeed was with a 6 iron, I was hitting it about 180 yards.
Not a bad swing speed with a 6 iron. The R300 is a pretty stout shaft. Did you go to an authorized Titleist rep? Did you try the PX 5.5? How was your launch/spin<back and side>, deviation, AOD, etc.?