I'm also doing IB at candi (there are a lot of us around here, it seems).
I can see why you might be worried about doing IB at a college that has just started offering it, but I have to say in some ways I think it's a plus. The college has a lot invested in the IB kids succeeding, and I think the uncertainty means they put a lot of effort in. Melissa makes sure she's involved every step of the way, and she tries not to let anyone fall too far behind.
I've got a bit of a different perspective from the other guys, because I did AS at candi last year. Although the IB did take a bit of getting used to (especially losing all the free time I had during the week), I'd still really recommend it. Along with Melissa and the other teachers offering loads more support, we've also built up a real sense of community in the IB group.
One of the things about candi is that it's pretty big, and as you're only there for two years you don't get time to get to know the people in your classes if you do A-levels. I got to the end of my AS year and realised I still didn't know most of the people in my classes - and whilst that was partly because I'm terrible at remembering names, it was also because there was only one person who was in more than one class with me. You're with the same people every day, but one of the advantages of being in a big college is that you can still get to know A-level students, so we're not totally separated.
On the subject of our ESS teacher, a lot of people have really taken against him, and I have to admit sometimes he can be annoying, but he's not always that bad. However, if you're really interested in doing proper science, I wouldn't go for it. It's sort of social-based/applied science as opposed to a 'serious' science, and although we do do some experiments I think we do less than the biology/chemistry lot.
Oh, and I just thought of another reason IB beats A-levels. This isn't true for the Anthropology set as their subject is really popular, but in Economics and History we have tiny classes - there are 5 people in my history class. This means you can't slack off, but all your questions get answered and we can have proper discussions. That might not be for everyone, but personally I think I learn better when we're talking, because I'm properly engaged.
And Clive - the history teacher - is a good person to know, because he's the EE co-ordinator, he's marked loads of EE's in the past and he also seems to know a lot about the university process.