Cancelling a contract if signal is bad?

Zack1

I'm at uni and the o2 signal here is great, but they won't give me a decent retention deal (unless I get an iPhone, yawn). I've found a deal on orange which works out slightly cheaper per month than the PAYG one I was gong to go to (PAYG is £10, unlimited net/sms & 150mins - the contract one is about £9.50 a month as it's got £250 auto cashback, 50 less mins and only 500meg net but that'll be fine), and it gives me a free phone which my friend may want.

Problem is it's on Orange and I don't know what the Orange signal is like here. I know last year I was on o2 and was one of the few people not to have problems with signal. Others on Vodafone had problems. Orange state "excellent" coverage in my area. If I got a contract and it wasn't usable in halls would I be able to cancel it? And re-port my number to Giffgaff (part of o2).

I know there are "cooling off" rules, but I was told before that they only applied if the sim hasn't been used - and to check the signal I'd have to use it. Unfortunately I don't have any PAYG orange sims lying around to test the signal with....