bristol for sure
no contest in my opinion. and that is all it is.
but i couldn't get past first base with oxford even on the phone. if you don't fit into the little box perfectly, they think something is wrong with you.
bristol is run by Alex, who has really flown some impressive hardware in the past and will listen and has the added ability of lateral intelligence. i.e. real world knowledge and can understand how a student may not understand after the first two attempts at a question.
if i had to do it again, and i'm glad i don't, i would use them again without a doubt. i will not even waste the cost of a phone call for oxford. though i did buy a few of their books. but you can use pilot warehouse for that.