I just went in February and had a better time than I ever thought possible. That place is truly special and truly one of a kind. Everything is about the golf and I wouldn't hesitate to recommend it to anyone. Already planning another trip for next February.
A couple tips that I wish I would have known before I went/lessons learned:
1. The third round of the day is free regardless of which 2 courses you played first, so if you can, schedule the Preserve for first thing in the morning (13 hole par 3 course) and then you can get 2 rounds in after that and the 3rd one is free. We missed out on the Preserve because we didn't know that and the rest of our days were packed, we could have fit it in first thing in the morning a couple of days.
2. Bring 3 or 4 people. I went with 1 other buddy and while I don't mind playing with strangers, you run the risk of getting paired with some really weird people. I get its a bucket list trip and destination, but we got paired with a twosome that was far more interested in taking videos and pictures than playing golf and it really slowed us down.
3. Bring several pairs of shoes (and nothing close to new. I wore a pair that was only 4-5 rounds old and they destroyed my feet and since have become the most comfortable pair I have after they were broken in) and don't be afraid to wear tennis shoes if they are comfortable. You're going to walk A LOT. We walked almost 70 miles in 4.5 days. Also bring multiple pairs of socks in your bag in case one pair gets a little wet. My buddy wore a pair of ankle socks and then a pair of tall socks over those and he seemed to love that.
4. Get a caddy. They are worth it. We would have been lost without ours and they make it more enjoyable with some history and they know those courses incredibly well. Ask for Bro when you call caddie services. He is one of the originals and he was great and learned both of our swings and distances after the first 2 rounds. The next 6 rounds he'd just hand us a club and tell us where to hit it. And it's nice not carrying your bag that far.
5. If you're going in December, you better get a good rain suit because the only real difference between peak season and off peak season is the amount of rain to expect. The temp doesn't fluctuate too much but the rain does, and Nov-Mar (I believe) are the really rainy months. We got lucky and got summer weather the 3 week of Feb and it didn't even threaten rain.
6. The punchbowl is perhaps the best part of the whole place and I wish we would have had more time to play on it, but we finished pretty close to dark each day. They really need to put lights on that thing in a hurry.
7. They have shuttles to drive you everywhere on property which is really cool. You just call them up and they come get you and take you where you want to go so you don't have to worry about getting anywhere and when you get liquored up at McKees you dont have to walk or drive home.
I think that's about all I can think of at the moment. I know a few other guys have been and will chime in shortly. You won't regret going, that's for sure.