It used to be that Uberti was assumed a step up from Pietta. Today, I think they run about the same. The distributor you buy from makes a bigger difference.
It seems that some
U.S.-side suppliers tend to get better quality imports than others. I own three Uberti-made revolvers right now, two Ubertis from a well-known muzzleloading shop and one Uberti from Cimmarron. The Cimarron was a full step above the others out of the box.
The two I did not get from Cimarron needed to be gone over when they arrived - polishing contact points, re-fitting the wedge, and in one case, re-timing and removing burrs from the frame in three places.
The Cimarron gun had somewhat sloppy wood fitting on the grips, but otherwise was fine out of the box. I have no real objection to that and it shoots really well.
I've also been to the Taylor's & Co. display at a couple gun shows. They seemed a notch above the usual Uberti, and on a par with the Cimarron.
Wherever you buy needs to have a return policy. Buying an Italian reproduction is a throw of the dice. It is very likely the gun will have at least one very minor thing off about it. It is somewhat likely it will have a substantial but correctable issue if you have basic hand tools and patience. There is a small but real chance there is something wrong with it that requires a return (I have encountered new guns with loose arbors).
My view is that we have better metallurgy today than the originals did, but that the hand fitting and finishing at the factory is a step down from the originals.
They're a lot of fun once you're set to go, and once you're proficient with them it will be immediately apparent why they wiped out the single shot pistols that came before them.
I am sorry to run on, but it's no longer a case of "Uberti beats Pietta". It's a lot about where you buy and who is distributing today.