My friend tried for Kingston but didn't get in. He does graphics, so it's a little different, but he's satisfied with the course. He doesn't have much praise for it, but it's done its job in terms of places next year. (He's going to Chelsea)
I, however, have nothing but praise for Kingston foundation. I'm also in graphics, but the people in 3D are, on the whole, loving it. I don't think that you would be wasting your time doing rotation; it all feeds into the work you end up producing, and it's good to get a grounding in several disciplines before settling, even if you know what you want to do, in my opinion.
Because the kingston course is small, you get to know pretty much everyone. Usually around 20 people do 3D, which means you get a tonne of tutor time. This is compared to (at a guess) 100 at LCC. We are also expected to be in pretty much 9-5 5 days a week, whereas my friend at LCC is in about 2-3 times a week. It depends what you're looking for in a course really.
I obviously can't make a fair comparison, because I've never studied at LCC, but Kingston seems far more tight knit, and I personally found the work at the end of year show last year at Kingston more exciting.