I attended a small school.. approx 1500 undergrads. My classes ranged from 4-30 people in size, but averaged about 20 or so. (My larger classes were the core, or survey, ones that everyon has to take).
The Good- I loved the small campus (like a 3 minute walk to ANYWHERE!). The professors are really involved with the students ...I even go drinking with a few of them these days! (i've graduated

). You get to know nearly everyone, especially if you have the same or similar majors.
The Bad- Occasional lack of things to do. Everyone went home on the weekends (which I still don't understand

). You get to know nearly everyone. Most of the people came from similar backgrounds (ethnic, religious, you name it) so you weren't exposed to a lot of different things unless you went out of the way for it.
The average sororit size was around 35-50 people depending on the year and semester. Greek life was TINY.. between 8-14% of the students.. and we didn't have any NPC or IFC organizations, so didn't have a lot of those big traditional greek things. We did have Greek Week, Greek Sing, etc. It was just different than most people's greek experience. (Not that I would trade my experience for the world! )
I plan on going to a big state school for grad school just to be different. I feel like I experienced one, and now it's time for the other.