I'm not a current student, but I have firmed 2nd year direct entry for Maths too, so I thought I'd give my two cents. I'm probably going to end up putting Kitchener House down as my first choice or whatever for all the reasons you stated above^. It's cheap, looks nice, sooo much closer to our lectures and stuff, self-catered (def a plus for me) etc.
When I visited, Pollock Halls looked really nice but not worth the price imo. Also I cba getting a bus to my lectures every day :P 7 years of secondary school buses are enough for me. The bus journey doesn't look too long though, if you do decide to go with Pollock.
With regards to the food served at Pollock Halls, I had some on the offer holders day and didnt like it very much. My mum didn't like it either, but that's just personal opinion really. Oh, keep in mind that you only get 2 meals a day, so you'd still have to spend money on lunch and snacks and whatever else you want. I just can't afford it really.
I wasn't too keen on the size of Kitchener at first - 60-70 people? You live in corridor-style rooms from my understanding though, so it wouldn't seem too bad?
What bad things have you heard??