Yeah, the Jewish community isn't too big but I would agree with the tight-knit part. We're not too big (about 4k undergrad), so if you want to be active in the Jewish comm you'll definitely get to know everyone. As for the level of students here... people definitely work very hard here. I was in the same position as you, I cruised through high school and got rejected by most of the ivies (Princeton was my first choice) but I came here partly because I wanted to avoid the grade inflation associated with them. I like knowing that when I get an A I've really earned it. I've definitely learned how to work here, and I wouldn't trade my life here at Hopkins for anything. It may not be for everyone, and in fact I hated my freshman year, but now I realize that it's one of the best decisions I've ever made.