Grinnell is a couple hours west of where we (wife and I) live. It’s between Iowa City and Des Moines, cities of about 200,000 and 80,000, respectively. The U of Iowa is in Iowa City.
Grinnell itself is small town/rural. Iowans are known for being nice. The school is known for its somewhat hippie culture and is quite far left generally, but not militant. It’s excellent academically.
Here are my impressions of the other schools you’ve just mentioned:
Middlebury - Outstanding in the languages, maybe the best. Strong all-around as well. Beautiful location. Balanced student body (for a LAC) between jocks, nerds, artsy types, crunchy types (I’m a bit out of my depth with these adjectives…).
Bard - I’m sorry but what has stuck out the most to me, based on reading years’ worth of comments, is the amount of smoking that goes on here – cigarettes and other things. I’m sure it has redeeming qualities too.
Kenyon – Another humanities powerhouse. At least as rural as Grinnell, maybe moreso. At least Grinnell is any easy/short car ride away from Des Moines and Iowa City.
Hamilton - This school was once two different schools, so there’s a sort of “two halves” feel to the campus. Hamilton is known for developing writing skills and is strong academically all-around. Like Middlebury, it seems the student body is fairly balanced for a LAC.
Bowdoin - I spent an hour dinking around the campus with my wife on our honeymoon (Boston/Bar Harbor/Lake George and places in between). I liked how flat it was and enjoyed some of the cool buildings enough to photograph them despite the drizzle we encountered. There is an Antarctica museum, which is neat. Bowdoin and Middlebury are age-old peers and of similar quality overall, but reside in differing environments.
Colby is another pretty Maine college. Like your other NESCAC entrants, they are strong academically. Also a fairly balanced student body.
The school’s teams are called the Mules, an obvious endorsement of interspecies breeding.
In terms of rigor, I would say none of them is as hard as Reed, Swat, Chicago or Carleton – at least based on what we read on these boards. In terms of intellectualism, being LACs, they have their fair share of it. But again, none is probably more intellectual than Reed or Swat, or even most of your other LACs. Of course, the only way to know for certain would be to look at the course syllabi for similar courses, and to read student reviews.)