Class size? Professors? Accepted at Isenberg

What is a typical class size ? (Freshman and beyond. )
Do TAs teach a lot of the classes? (I looked up some stats for every school I was accepted to and there was nothing about umass Amherst. Strange!)
Are the professors helpful, interesting, interested?
Does it feel like a large state school or like you can get individual attention?
OOS student accepted at Isenberg thank you!