I'm on my second pro. The first I had was an early run from April and really didn't have any issues. I had pulled the ball guides up on that one and my slimer seemed to work okay. Really dialed that one in well without too much effort and sold it to a pinsider knowing I was getting another down the road anyways.
The second one I just opened was from a July shipment. I tapped the lane guides up because of the ball frog leaping. It came with the new slimer mech which has been excellent. The ramp however, has been giving me a little trouble. I've had the ball go up it several times around the entrance gate and spin back down the ramp back to the flipper. The other weird one is the ball is coming to the end of the ramp and spinning to the farthest inlane (instead of the inner where it drops) or sometimes the outlane, which really sucks. I've been trying to remedy this and will look into it a bit more. I was able to loop 25 supers in a row on it, so it's still shootable, it's just once in a while pains I don't recall from my first GBPRP.
Other than those issues, it seems to be fine, playfield looks good, time will tell.