Lake Placid or Utah?

Utah was my first.  Yes it is brutal.  The water is freezing and the hills just keep on coming.  The thing to keep in mind when considering St. George is not the course, but the weather.  If it was any other day but that Saturday I would say most people would have DNS.  The days leading up to the race and even the last leg of the bike the winds were brutal.  I am a big guy 250 lb and I was getting blown all over the road the last 10 miles.  However,  I would recommend it.  I had a great time. St. George is a little hard to get to if you can't drive there, but it is great place.  I plan on doing it again in a couple of years. 

Having done IMSG, my take on it is that the run is really the killer.  I came off the bike badly dehydrated, but probably could have recovered on the majority of other IM runs...St George starts with three miles of mostly nonstop uphill, culminating in about a 1/3 mile 10%+ grade climb (which you'll do again on lap two) and then just carries on with continuous rollers and one very long grade (again you see it on both laps, going down then right back up).  I'm a strong runner (solidly sub-4 for marathon) and trained a lot of hills in preparation, but it still wore me down after a tough ride.

It's all doable, but you need to be prepared for a demanding run and I think a lot of people in cold weather localities may not get in the hills they need on the bike over the winter with such an early race date.  Just some things to consider.

Do it where you know best, Utah.  It'll take a lot of adjusting to a new place out of the mix.  My .02.