I saw these posted in a recent thread:

http://sheldonbrown.com/harris/wheels/622.html

36 spoke with the Mavic 319s, which, along with 719s, seem quite popular. What I don't know is:

What is the difference between WE639, WE632, and WE634?
How do I know if I have 130 or 135 spacing?
Anybody have experience with these? Hold up to abuse?
What do I need to know about swapping out the rear wheel? Is it easy to transfer the cassette?

Any other suggestions in this price range?