the answer is "not a damned thing". :-) It's all hype. Colt's DA's have always had a rep for going out of time with fewer rds than the Smiths. The rugers put them both to shame in that regard, but the smith's trigger pull will always be a touch smoother. Reaslically, the Python is overprice by a factor of 10.
Can I buy a new Python? No? Why not? Could it be that Colt's design was a POS and the market spoke loud and clear?