I haven't seen it at UO but we experienced USH's version last week. It's AMAZING.
There's a handler (dude dressed like Chris Pratt) and every time we've walked by, the CM doing this has been completely committed to the role. LOVE THIS.
He sure is! All of the TMs involved in it are 100% committed. It's so cool.
I am a grown adult and I was cringing with the velociraptor behind me during the photo op. The TMs at USH described to me the difference between theirs and UO's, and it seems like at UO it's a bit less "wild" in feel than at USH. At USH the raptor walks, with chains, past the whole line of people waiting for the experience, then they release the chains. We were first in line, and I was actually nervous, and nearly asked them to put the chains back on!
Please note I'm NOT a character person at all, I don't like them, and gimmicks irritate me, but the dinosaur stuff they do* is truly impressive.
*in December 2010 my son and I happened upon a randomly reopened Triceratops Trail, and it was fabulous. We were so sad to find out that they decided not to go forward with it...but I'm going to assume they knew, even back then, that JW was going to be made and they would have something "better" to do with "live" dinosaurs.