Sorry I missed this and did not respond earlier.
I have one of the less expensive versions, a Cimmaron, for a couple of years with which I have been satisfied. I have an original 1876 to compare it to which is nice. Unfortunately, the original is not available right now so I have go off my (faulty) memory.
The Cimmaron replicates the Third Model 1876 with the dust cover rail milled into the receiver. The Second Model had the rail screwed into the receiver and the First Model had no rail nor dust cover. I have seen only two other 1876 replicas and all were of the Third Model.
The case coloring on the Cimmaron is fairly subdued, unlike on some other reproductions I have seen. I have not handled the gun a lot so cannot speak authoritively on how well the coloring will hold up. I'm guessing not as well as the original which seems to be the case with most lower priced repros.
The bluing of the barrel is lighter than the original, dark blue like many current rifles rather than near black as with some modern rifles. It doesn't look bad and it flows with the case hardening pretty well.
The wood is pretty plain and has a sort of shiny finish. It isn't glossy but it isn't hand rubbed oil either. I don't mind it but a purist might turn up their nose at it.
The buttplate is my only real objection, mine appears plastic rather than metal. It also has a slide rather than trap door for the storage area in the stock. This is merely a drilled out area in the Cimmaron while the original was drilled to fit a 4 section cleaning rod.
They are both pretty heavy guns, they remind me of carrying my 10 ga Ithaca autoloader. Like the 10, they are very easy on the shoulder to shoot.
Both guns are in 45/60 which is nice as brass can be easily made from 45/70 if necessary. I bought 60 rounds of 10X black powder ammo on clearance several years back when I bought the original. Those were 350 gr lead bullets rather than the original 300 gr but they shot decently. With the replica, I bought two boxes of smokeless rounds made by Jamison. I don't recall what bullet weight was used but it was lighter than 350 grs and was plain lead. I bought both types from MidwayUSA.
My reloads initially were with black powder as I did not want to stress the older gun with smokeless. I just filled the case with FFg until the bullet compacted the powder a bit and let fly. Now that the original is not here I've been playing with Reloder 7 and 300 gr lead bullets. I'm shooting 3" -4" at 40 yards with .458" bullets which I'm not satisfied with and need to try .459" and .460" as well as a gas check design. Plain lead bases worked well with black powder and .458" bullets. Jacketed bullets are acceptable in the modern gun as the barrel steel is hard enough to handle the friction. The original has a much softer steel which erodes much faster with jacketed bullets and/or smokeless powders.
I recommend picking up Lyman's 48 or 49th edition of their metallic reloading manual as there is an article on loading the various 1876 cartridges. There were some smokeless and a couple black powder loads listed. Mike Venturino had an article in either Rifle or maybe Handloader magazine on loading the 45 caliber cartridges in Winchester lever guns. His book on buffalo rifles had a small chapter on the originals but no replicas were mentioned as they had not come on the market yet. The later magazine article covered this omission.
Hope this helps.