Is Talk Mobile trustworthy?

I am planning on getting the HTC Desire S, i was going to get it from the carphone warehouse but i have seen a deal on a website called 'Talk Mobile' that is much better, but it seems a bit too good to be true and i have never heard of this website before so don't know if its trustworthy, if anyone knows please tell me and if you know any great deals for the Desire S please tell me.