I would put my '72 Open Top Colts in .44 Russian against any adjustable sight revolver out to maybe 20-30 yds, beyond that it may be a power issue anyway. I use a pair of '51 Navy Conversions with Black Powder .38 loads for my Gunfighter class shooting, and they very rarely miss. Of course, that is at the close SASS targets. If you are an Old West purist than there is no choice but a fixed sight. If you are after target shooting accuracy and/or distance shooting and dont care about pure Old West, then perhaps the adjustable is the way to go. But personally, I would not say that fixed sight revolvers are not capable of very good accuracy. More than likely, it depends on the condition of your eyes and the steadiness of your hand!!!
In so far as quality issues with Uberti or any other maker, they can all have a problem here or there. I have one of the older ASM Schofields and no matter what I do, it shoots 3-4" to the left. I will have to make some sort of new front sight. But, I also have a new Uberti made No. 3 Russian and it is a tack driver. Go figure.