I have 4 1858 .44 and 1 .36 all pietta, that I have purchased in the past 15 months, all good straight shooters with the exception of the .36 which shot about 2 inches to the right which I was able to correct using a small triangle file on the rear sight, all the guns sot a little low, but easy to correct with a file on the front sight. The only uberti I have it the 1858 revolving carbine, the frame on the uberti is more streamlined looking, and the outside of the barrel is is slightly smaller in diameter, I am pretty sure the pistols are probably the same, also the action on the uberti was great out of the box, The pietta’s had a creep in the trigger pull but I have been able to get rid of that as well, The pietta’s have their name and for black powder use only stamped on the barrel, the uberti dose not.
One thing to conceder with the remmy, To get the full experience of it you should have at least 2 extra cylinders, I think anyway, so if you plain to do that and price is a consideration, I would suggest cabelas for pietta the guns are cheeper they carry the cylinders and spare part kits. If you want a gun that is probably a closer replica of the original, I would go with the uberti, and midway is great, fast shipping great customer service, thats my experience anyway, good luck either way I you will have good fun shooting.