I've done 2. Whistler and Seattle. Let me tell you this. Where you do it really determines your opinion on the "quality" of the race. I'd heard Whistler was the toughest course they've ever created. Let me tell you...I trained hard for it, and it was the most physically difficult thing I've ever had to accomplish. Seattle, I didn't train as hard and smoked it. I credit this completely too the elevation gain at Whistler. I had a really good time at both, but I echo the sentiments of getting out early if you are serious about it (which most of us were). We went in the second wave both times and was able to maintain a pretty good pace. We finished in about three hours for both. It's definitely a "team" game though, so make sure you have partners in the same physical shape as yourself. If you have any other questions, just shoot me a PM.