In the end, it depends on what you are looking for and what your priorities are. Yes, the modern reproductions of the old west designs will handle ammo levels above recommended Trapdoor levels, but are those going to be of any benefit for what you plan to do??
I've had some hands on experience with the Sharps repro guns, and some others, they are tremendous shooting machines, fine examples of the design era combined with modern steel alloys.
But, they're not what I consider good hunting rifles. Long barreled and generally heavy to very heavy, their great for extended shooting, much less so for being carried alot, and not well suited to stalking, or hunting in the close ranges of woods and brush.
If you want the old time look, its there, in spades, and they perform as well (and usually better) than the originals did or do today.
If you want a bench gun, or off shooting sticks and shoot all day without getting beat to death, the "Buffalo Rifles" are great.
If you want a gun you can carry for miles, up and down hills and mountains, shoot easily offhand at need and be handy in thick cover, the buffalo rifles are a poor choice.
I've had a Ruger No.3 carbine for a long time (will be 40 years next year). MY rifle was used (looing new still) when I got it, and the previous owner knew what they were about, and apparently liked heavy loads. Mine has a nice thick ventilated recoil pad and that makes a world of difference.
My carbine has a 22" barrel but the single shot design means the over all length is the same, or shorter than many rifles with 18" barrels. Its light (in the 6lb range) and easily scoped if that's what you want. It has a great trigger, and is accurate, enough that I've put 3 shots into two holes on more than one occassion. I think its a much better hunting rifle than a buffalo rifle, and I'm confident I could take a buffalo with it.
What i wouldn't want to do is shoot a couple dozen buffalo in a day the way the market hunters did. (also, will NOT shoot heavy loads from the prone position with that rifle, EVER!
)
So decide which things are most important for what you want to do, and choose what best suits your wants.
Oh, and btw, based on my experience with the Sharps repros, while it usually won't happen, it is possible to get a round into the chamber with the rim underneath the extractor. I've done it (unintentionally, of course). If this happens, the action will not close. Easily cured, not a deal breaker, just a quirk that can happen when the stars line up the "wrong" way.
operator error is the cause.