I did it last year. There's a thread out there somewhere with my comments on it. It's a month earlier this year so weather shouldn't be as brutally hot as it was last year.
Swim last year was very tactical, in a river with a fast current (about 2-2.5km/hr). If you didn't plan your swim carefully you could get spat out downstream. This year's swim is the same river but all downstream, so expect a very fast time. I used a full wetsuit, was pretty warm so I pulled open the nexk seal a few times to let in cool water.
Bike map on the website hasn't been updated yet but the ride last year was mostly flat, a couple of short climbs near Shi Shan village but nothing very steep. It should be quite a fast course, if the weather isn't too hot (I was already cooked by 100km last year - it's the only IM where I've had to dismount and walk through aid stations to sponge down!) Most of the roads were in excellent condition, very smooth expressways, and road closures were very good
Run is flat except for one little hump backed bridge, which you'll be delighted to see as it's just before the finish!
Have you decided where you are staying? Check the hotel locations carefully - some are a long way from the transition area. I stayed in Crown Spa Resort, nice place, suitable for families, only a few km bike ride from transition and they also organise shuttle buses to race start & finish.
