In order of quality, and the make/model of the original is not really a factor:
For Colts, the best quality for fit, finish and authenticity is the 2nd generation series from 1971 (Colt 51 Navy), 1974 (3rd Model Dragoon),1978 (1860 Army) The 3rd generation beginning in the early 1980's is not as well made, and by other mixed parts vendors. The Color cae is marvelous on all these, but the 3rd generation guns are overpolished, before assembly, so corners are rounded, etc, and the physical details are not as authentic, as to triggerguard size, nickel instead of silver plate, missing capping grooves, unspiraled cylinder pin relief, loose cylinder pins, and others.
Uberti made the parts for the 2nd gen Colts, and the 3rd gen look like a mix of ASM and Pietta. The assembly finishing of the 2nd gen was by Iver Johnson, who did a very good job. The 3rd gen was by Colt Black Powder in Brooklyn N.Y., who might have been better advised to make shoes or something.
Top quality and authenticityof the Italian imports would be, Ubertis by Cimarron or Taylor, then Uberti itself, of either Remingtons or Colts.
Next (now) Pietta, though some major parts are not interchangable with Uberti. Piettas aren't as authentic in some shapes and contours. Older Piettas were rougher in final finish.
Armi San Marcos is further down the list for fit and finish.
EMF or DIXIE quality depends upon who made the gun in Italy to start with.
Makers who produce things like 44 cal Navies aren't much into authenticity. If I want a 44 Colt, I would get the 1860 Army, why would I want an overbored 51 Navy?
No brand of brass framed revolver is going to stand up to heavy use, but they are pretty.
All of them could have been better, and the quality of the conversions and open-tops is quite a bit higher than the percussions, both for fit/finish and steel hardness. (as indeed they need to be to shoot smokeless).