I had an Uberti factory NMA conversion for a bit, and it was OK, but seemed like it was significantly bigger that the percussion. I know it is supposed to be 10% bigger to accommodate a 6 shot .45 Colt cylinder, but to me it seemed even bigger than that!
I have four percussion Pieta that I Kirst Konverted. I think I enjoy them more, because I am the one who really created them. My two 1860s (8" & 3") have replaced everything else as main match pistols. They are uber-cool, and totally in character with my 1869 Persona, who had private .46 rimfire long cylinder conversions to go with his 1860 Henry. The .46 caliber (with a .456" bullet) conversions were far more accurate than the LCC that used .44 Rimfire, as that .438/.440" diameter bullet would bounce down the .454/456" bore of the Colt 1860s and Remington NMA.