I live not far from Universal Studios Hollywood, and this might just be my favorite theme-park ride ever. Glad you east-coasters get a shot at it now.
It's a combination 3D motion-simulator and fast-paced dark ride. You get 3D glasses and ride a vehicle on a track, through a combination of sets and screens, till your vehicle parks itself in front of a massive 3D screen, at which point it becomes a motion simulator, pitching side to side as appropriate, and with added practical effects like heat and steam. The scene ends with a robot shoving you into the wall or something like that, at which point your car continues along its track, crashing and spinning through walls till it parks in front of another huge screen where the next big thing happens - there's maybe 6-8 of the super big screens total, and a giant practical Megatron at one point.
Like Bayformers or not, it's a blast to be inside of a simulation with them. There's even a moment where everything in the simulation briefly switches to slo-mo and back for the true "living in a Bay movie" effect. Also, Frank Welker is Megatron again.
When I first went on in, the only thing I was pissed off about was that they didn't have a toy of Evac, the robot/car you ride in. That has since been remedied.
Also, Floridians, in Hollywood they did a secret soft opening, randomly letting guests in to try it out in the days before the official bow. So if you're in the area before June 20th, keep your eyes open.
The Transformers costumed characters in the park, though, are pretty bad and can barely move. Arms go up, arms go down. They're as articulated as a Batman toy aimed at kids.