Hi, Bags! My tips (some of this stuff is probably well known to you):
When you get there, there'll probably be a line by the door on I, but if you go around the corner to 6th, there's an entrance that's partially below street level. If you go in that entrance, you can stand in a waiting room where you can buy drinks and you're out of the heat/cold/weather (unless you're late and the waiting room is full, of course).
Speaking of which, I think it's well worth getting there early, before doors open certainly. I've gotten there late, and I ended up sitting in some weird spots that did not have good visibility.
I prefer the center and left side on the floor (facing the stage). The right side is not as good, IMHO.
If you have to go for the balcony, go for directly across from the stage, not the sides. I've found it very difficult to see on the sides (unless you're in the first two rows of the balcony). If you're even 3 or 4 rows back, it's a weird angle such that you can't see half the stage unless you stand up. And then you feel like a jackass standing up directly in front of people who are sitting down.
Just my two cents,
Ed