Well, to add my 2 cents to this thread, just finished the "basic" course at Lime Rock yesterday. It was absolutely awesome. Yes, the track is shorter, minimal/no run off areas, but we still got to 120+ in the main straight, and IMO I thought it was even better as a first-time track since there is less to learn for curves, etc. So you really get to hang it out pretty hard, and in the GTS it was friggin' awesome. Got a few taxi rides in the SLS BS, and in the GTS, and that was awesome too.
Can't recommend it highly enough. Outstanding. It's too bad they don't promote it to new AMG owners, as it definitely helps establish brand loyalty (yes I'm now looking at the 16 GTS on line...) and I'm sure it is well worth the significant expense on their part.