I just saw PR in IMAX 3D. Visually, it was beautiful. CGI was great. Out of IM3, STID, and MoS, PR had the best use of 3D.
The first robot/monster fight was awesome, but I felt it got a bit boring with each fight.
I loved the first Transformers movie and was hoping I would get the same enjoyment from PR, but it had none of the charm, was very predictable start to end, and I didn't really feel anything for the characters.
I'd give PR a C+