My 2 cents on the size issue: I think Stanford (with 16 incoming students my year, ~70ish grad students total) is a good size. Small enough not to get lost in the crowd, large enough to allow for reading groups and student seminars.
By the way, does anyone have any idea how transfers work?
Grad school transfers seem to be extremely rare and decisions made on a case-by-case basis.
The only department I know which seems to take transfers on a regular basis is Berkeley, but they seem to only take students with outside funding. (And mostly students from other top 10 programs after they have failed their qualifying exams at home.)
I have another friend who tried to transfer after his first year because he didn't like the atmosphere in the department he was at, but he got rejected everywhere.