I went to Brasenose, and I certainly am not a party animal at all. That said, I think a pretty good contingent goes to the clubs, so you won't be in want of company if you do decide to go.
If you're looking for a large college, I wouldn't recommend Brasenose - it's relatively small. I also wouldn't say that we have great food (I personally think it's fine and Formals are relatively cheap, but I also have a relatively high tolerance for bad food, so take it with a pinch of salt), but I would say we have some of the best locations in terms of undergrad accommodation. I didn't think Brasenose had that much of a "private school" vibe, but that's just me.
Personally, based on your criteria, I would actually recommend Worcester: huge grounds, nice food (not so sure about normal hall food, but I love Worcester formals

), and lots of en-suites!
Also, you're right that you shouldn't play a stats game, but having more people in your year might be a legitimate factor in any case. I went to a college with a large intake for my subject, and I quite liked the resulting camaraderie.
Correct me if I'm wrong, but isn't it the case that for Arts subjects generally, you're very likely to get a 2i, but less likely to get a First or a 2ii (or below) as compared to Science subjects? At least that's how I understood it

Or I might just be confused.
I'm not sure how it works for other colleges, but at Brasenose, it only really matters if you get a Distinction (or get promoted to Exhibitioner by other means). No one gets penalized accommodation-wise for getting a 2ii equivalent (or worse). Or rewarded extra for getting a high average/ university prizes. You're right in that statistically, getting a First/ Distinction is more difficult in Arts subjects (and sad to say, Law is somewhere at the bottom in terms of First/ Distinction rates, although the faculty's supposedly making a concerted effort to mark more generously).
Personally, I really like the system used by Magdalen: Random ballot for 2nd year, and then reversed in 3rd year. I think that's pretty fair to everyone

Completely off-topic, but can I PM you regarding the BCL?
