I shot the S2 and really enjoyed it. The problem, for me, is that if I had to rely on the S2 on a job, my ulcer would come back. I really don't think Leica is a professional camera company. Don't get me wrong, I've enjoyed my M8 and my M9, my M4-P and M6, and I've shot all of them on jobs, but in no way is Leica's support or reliability at the level required of a professional product. Maybe support is different with the $4kUSD warranty, maybe the electronics in the S2 are more reliable than those in the M8 and M9. I'm not sure, but I know I won't pay Red Epic money to find out, especially with the proven, confidence inspiring H4d-40 and D3x out there.
That being said, a nice camera.