I've done the 2.5 hour twice and the 5 hour once. I thought the 2.5 hour one was better, I started to lose interest as time went by on the longer one, because it's the same but dragged out. I only really went to see the ER stuff and I'm glad I did.
I put the next bit in white, because it contains spoilers, incase you didn't want to read. Just highlight to see.
The tour guides are great, all the times I went they were a lot of fun and really chatty. It sort of a whirlwind tour, on a golf buggy, of most of the sets and prop houses they have on site, there are some photo opportunities along the way and some time for questions. I found most of it quite fascinating. Then they take you to see some famous cars and there's a small Harry Potter museum, where I believe you do get a free photo of your group infront of the Hogwarts Express. Unless they changed that...
Most shows are on hiatus in the Summer, although last August when I went there was some filming taking place whilst I was on the tour. Some crime programme, don't really remember. Basically though the tour guides know to stay well away and usually they won't let you stop to look for more than a couple of minutes. Let alone get close!
