Have you visited these schools? If not, can you? I would drop any website content/appearance issues as a factor in your decision. I wouldn’t call the overenrollment situation at Midd a ‘scandal’, but it has impacted housing to be sure. But, Carleton has overenrolled in some of the last 5 years or so too (google is your friend), including prior to the pandemic. Read the school newspapers to see how overenrollment is impacting the students.
If costs are a consideration, how does net COA compare?
Carleton is far less remote than Middlebury, with relatively nerdier students. Both have harsh winters. Carleton is on the quarter system which some students prefer, others like to avoid.
Have you looked at the gen eds for each? Looks like Carleton has a FL requirement for most students (there are ways to test out, but in most languages have to demonstrate competency to 4th level, and 5th level in Chinese, Arabic, or Japanese), whereas at Midd it looks like one can avoid taking a FL.
Have you looked at the psych major requirements for each? Psych prof backgrounds and research? Full psych courses and how often each is offered?