I've been using and original P2, since you could get p2's (I have serial number 40 of the original P2 stock) and they came with the original 314 shafts.
When Royce and Don (Don Owens and Royce Bunnell) were first making the OB-1's, they would on occasion have me try some of them and I'd give my opinion.
At first I was VERY skeptical. I didn't like them and didn't think they had a chance. Now I know both Don and Royce. (my wife played scotch doubles with Don Owens last year at the BCAPL Nationals. BTW.. they took 5th-6th, loosing to Royce and AKA Trigger) But I digress...
As they made improvements to the OB-1, I was slowly... every so slowly and begrudgingly won over. Currently, I regularly help out at the OBcues Ladies 9-ball tour as a referee, so I have been around OB cues and there products for some time. I still have my P2 and use it as my main playing cue.
However, I also know that the OB-1 was sent off to be compared with the 314. The company that does the testing, is made up of several of the originators of the 314, but they no longer work FOR predator, but do have some very close ties.
When they tested the OB-1 vs the 314, they would not give OB Cues the results for some time. Shortly after predator released the 314 v2, they released the results....
The OB-1 had better performance, I.E. Lower deflection etc. than the original 314, but fractionally lower performance than the 314 v2.
So.. what does that mean to you and me.. Basically.. it's a coin flip.
What OB cues suggest, and it's how I became a fan, is come out to a show, or find someone that has one, or will let you hit with one, and try it for yourself.
I can verify that OB cues and shafts are 100% made in the USA. They are very proud of that and it will not change while Don and Royce are running things.
As far as the OB-2 vs the Z Pro, I don't have any info on that from Royce or Don. I have not talked with them much about it. However, they will be more than happy to let anyone know what they know.
Like I said earlier, I have an original P2, and like and play with it every day. I also have a filipe 8 ebony point cue that I put an OB-1 on, and it played very much like my P2. I use it at home on my table, and it does what I expect. I really don't tell much of a difference from either cue.
So, I have to agree with Royce and Don. Go hit with one. See what YOU think. I started off not wanting to like their stuff, and now I find myself liking it very much indeed.