Rob,
I like the BPCR very much. I've had it about a year but have just recently begun shooting BP in it. I have learned alot but have much more to go. The sights work well for me but I have nothing to compare it to. From what I hear they are a middle price/quality type of sight. Not as nice as MVA or Baldwin but much better than what comes on the Italian imports. As I posted earlier, I am just starting developing a load with the 349c and Swiss powder. So far I am happy with the groups I am getting, 3" high and 4" wide at 200 yrds. That is by far the best group I have gotten using several different bullets and Goex FF. As far as caliber goes.... If you are recoil sensitive you might want to go with the 40-65. If you can take a little recoil the 45-70 is hard to beat. From what I have found, the Brownings' 1:18 twist needs a heavy bullet to be accurate with BP. It needs a bullet in the 500 to 540 gr. range. The 40-65 will need a bullet in the 400 to 420 gr. range. NEI makes some very good moulds for both calibers. Hope this helps.
Bill a.k.a. "Old Jules"