FCK,
From a strictly mechanical standpoint, Pietta guns are, in my opinion, the best value for dollar for CAS use, on the market today. For the most part, they are also very close in dimensions to Colt as well.
Out of the bag, Pietta SAA copies are at about the same level as most of the Importers "match ready" guns. They (Pietta) require much less work to make them superb. Pietta was smart enough to go to the coil spring and plunger for the hand well before Uberti did. There was also a short period of time, Uberti was incorporating coil and plunger with the Gripframe screw, which, is not a very good idea as the plunger is not centered on the hand. Over the last couple of years, Pietta has also been marketing guns, specifically intended for CAS and in no way do the guns mime Colts. Wide triggers, wide hammers, Army style grips on SAA copy frames, thunderer styled short barrel guns for mounted shooters, well timed and set up from the factory. The only real problems I've personally seen have been some recent examples with odd unfinished machining. I would expect that comes from selling everything they can make in a production "run."
I have personally been impressed with their Percussion guns as well. a couple of seasons ago, I switched from cartridge guns to Cap guns and found Pietta guns to have fewer mechanical issues out of the bag than Uberti. And again, Pietta has been catering to the CAS shooters and "fun" shooters much more than "Traditional" shooters. As examples of their .44 "Navy" guns attest, as well as their "Snubbies." I personally shoot their 3 inch 1860 and 1851 Snubbies in Frontier Cartridge Gunfighter and it is a gob of FUN!! While several of Pietta offerings in Cap Guns are not necessarily "historically" correct, they are a ball to play with.
Coffinmaker