It's my last day tomorrow actually and I have to say, definitely apply, it's been a brilliant 5 weeks. I'm working in molecular biology and what we were supposed to be doing was clone a gene, clone it and transduct it into some urothelial cells to see what happens if they over express said gene but it's been a bit of a polava so we've spent the past 5 weeks trying to work out why the heck nothing works. >.<
I got in really easily, because I've had personal problems and I was the only applicant in the school (I went to the same lab as last year's lad). It really just depends on where you are and what not.
Also, you should bear in mind that most things in the first few days should make no sense to you. I literally had to read books designed for a microbiology degree and loads of papers to boot in order to get some zemblance of an understanding. By the time you leave however you should be taking in their language (I use acronyms for everything now a days).