I have used the 314 2 for years and I switched to z2 shaft roughly 6-8 months ago. The question for this thread was, "Do any pro's use z2 shaft in real competition". The answer is yes. Mike Davis does as someone else noted. The guy might not have a conventional stroke but I've played with...
I own the quietroller 2 cue with both 314/2 and z/2 shaft. I like 314/2 better plays more like a traditional cue.
Things I like:
wrapless
good feedback/ good feel
very well balanced (most balanced cue I've played with)
stiffer/firmer hit
feels like one piece cue
deep grain
simple yet...