Did it last year (2007) and doing it again this year. Swim course is very simple and easy to navigate, first 10km of bike is flat then VERY hilly!
It's either UP or DOWN - pretty much relentless - I logged 5,000+ feet of climbing. Be prepared for "The Hammer" - short but nasty climb ... I was down to 4.5 mph seated ... and the fast 10km return into Wiesbaden ... I hit 47 mph.
Run is 3 laps - the park is quite challenging as it is not flat either!
We stayed at the Crowne Plaza.
Beer is excellent - especially the Wheat Beer. Lots of nice small restaurants - last year there was a wine & food fair on in the main square.