Off road race, usually technical terrain, usually lasts 2-3 hours. Sometimes part of the course runs on a motocross track. The range of courses that fit into the "hare scramble" catagory is pretty wide.
Some of the races AMRA puts on fall in the Hare scramble or Desert Scramble catagory. C class guys run 2 hours, A's and B's go for 3. Holy Joe was considered one. I believe the next race (in Utah) is a hare scramble as well.
I raced a 93 KDX200 in hare scrambles for a couple of years and it was great. Never had a mechanical failure with the bike. Even now that I am no longer racing hare scrambles, everything I ride is still hare scrambles. I have logged several thousand miles of hare scrambles over the years, and all have been on KDX's.
Here on the east coast, most hare scrambles consist of tight, rutted, rocky, rooted, snotty, nasty, tree infested torture chambers. That's just riding. For the race, throw in a few hundred racers. Gotta love it.
The tighter the terrain, the more competetive the KDX will be. If you are in Georgia, I would expect your terrain to be pretty tight on average. You already have the bike, so go ahead and race it. You will probably want to modify it a bit with some simple bolt ons if you have not already. Race it for a season and then decide where you want to be with your racing. If you start chasing points and really get serious into it, then you will probably want to upgrade to more of a race bike. With stiffer front springs installed, the KDX has more ability than any legitimate C class rider can muster up.