I'm late to this party, but will relate my 2 cents worth of experience.
45-70 disease is as infectious as 30-30 Marlinitus and cast bulllets.
Aside from being a delightfully versitile round, it's as easy to reload for as any straight wall pistol round, or .30-30.
comments on arms: All of mine have been bought used or horse traded for.... so they can be had relatively cheap.
Pedersoli Sharps: any one of the four I have will shoot along side any other of it's type, and the fit and finish is generally better than most these days, but perhaps not quite the museum quality of the Shiloh or C. Sharps. The extra effort required to bring the action to battery is part of the fun. One of the four needed a burr polished off the sear, and while I was at it I polished all internal mating surfaces. IT IS REALLY NICE NOW.
Pedersoli Rolling Block: Ditto notes from the Sharps
Ruger #1: The two I have (as well as the third in .416 Remington) are all excellent quality shooters, and I feel a little less finicky in this caliber than in lighter bores.
Browning 1885: What's not to like? Nostalgic, beautiful finish, beautiful craftsmanship throughout, and a great shooter. However, the nice looking crescent buttplate coupled with a lighter weight more comparable to the Ruger will limit your daily round count.
JM marked Marlin Cowboy: Wow.. what fun guns with vernier sight. Both shoot better than I can hold, on par with the Sharps out to silly ranges. The weight of the sharps gives it an edge far out , but for practical ranges accuracy is comparable with loads they like.
JM marked Marlin Guide Guns: Same comments as Cowboy, in microgroove as well as ballard rifled models, blued and stainless. Much more handy than the Cowboy models and more likely to be work guns,,,and they're fully up to it. First shot with my first one at 200 yards at a pig with a 400 grain cast bullet held 4" over the shoulder..... bang....SLAP.... flop. Impressive
Thompson Contender Pistol.. Amazing one hole accurate, but not for the feint of heart. Three shots and three weeks for finger recovery. The trigger gaurd beats you third finger to a numb pulp after three shots. However, you should not need more than one, right?
Thompson Encore Rifle: Sweet shooter, though the break over action is a nuisance when shooting at the bench.
Having said all the above, I usually grab a beater 336 30-30 and a handful of rounds loaded with cast slugs when I leave the house. Good ol' truck gun that just cannot miss. likie an old dog, it just loves to hunt.
Hope these humble comments help.