calkid

first of all, i applaud your desire to step out of comfort zones and explore other social niches.

i can't give you much help on the strategy of choosing between these two places, but i'll throw in random bits of my perspective on things.

here's my spin with a focus on food:

i don't know much about how co-ops run, but i would be wary of the food if you're supposed to pitch in for the groceries and eat there every day. Some people can cook, some can't. I just wouldn't leave it as a variable to only be able to eat well on certain
days, ya know? with the theme housing, on the other hand, you obviously get the standard meal plan and great food (fantastic salad bar and vegan/vegetarian stations as might have heard of. in fact, we're ranked 3rd best "veggie friendly college" in the nation by peta2.com). also, there's food when you want it and wherever. bottom line of what i've said is you get quality food and convenience w/ the theme housing. - oh! and the choice to eat meat as well!

with regards to social atmosphere:

i believe you are thinking too much about how either place would fit your ideal perspective on life. you can't predict how that will turn out b/c there are simply too many variables. are they openminded? or are they closeminded? are they politically neutral? or charged? honestly, there will be an even mix, you know that. you can hang out with who you want. and isn't being open-minded something you admire? i'd stamp this as a non-issue.

all in all:

there are tons of variables in making this type of decision and really only a few will make the biggest difference. the concern of how you will fit in is very important but an unsolvable problem. find some other variables that you know are certain and base your decision on that. for instance, for me, the convenience factor of DC's would tip the scales overwhelmingly.

but if you can't find any, go with the gut feeling.

i hope this helps somewhat. good luck