UAB Master,
Hello from Hoover, AL!
I've stayed in both loops. 2000 sites are more spacious, more out in the open (as opposed to shaded) and you have the benefit of two bathhouses. You are a little more set off from the core of the Fort (main pool, Trading Post, movies, etc) so it's peaceful.
1500 Loop has fewer sites which are generally not as big, heavily shaded, and shares a single bathhouse with the 1600 loop. You are across the street from the main pool, movies, Trading Post, etc..
All in all I prefer 1500. Especially any of the sites on the outside of the loop (as compared to the inside of the loop though I would take those too over any 2000 site). At this point with kids, I like the walking proximity to the pool and campfire/movie. Some sites like the one we had in 1500 on Thanksgiving Week 2009 back up to the canal which give you a water view as well.
It's your choice - there's no wrong selection because both are great but that's what I'm thinking right now
Bama ED
PS-Can you help my son get some scholarship $$$ or grants at UAB? He's a junior at Hoover High School and we visited last Saturday for UAB Days. I have no shame (as you can tell) in asking so it's worth a try!