My Indian Bess seems to shoot fine. I haven't had it for long and have only shot loads with up to 90 grains of FFG so far, but so far it's worked fine. There's only been one confirmed kaboom with these muskets and a lab determined afterward that the metal wasn't to blame. It appears to have been due to poor maintenance and possible overloading on the part of a reenactor.
As to getting what you pay for, the trigger on mine when I got it was beyond bad. It was so awful the gun was almost unshootable, (easily over 30 lbs.). With some work though I now have it down to around 5-6 lbs and smooth. The inletting on mine is fairly poor as well. The Indians inlet with hand tools and it shows. There aren't many big gaps where the wood meets metal on my stock, but there are a lot of gaps that probably measure around 1/64" or slightly more. Now that may sound like I'm nitpicking, after all 1/64" is practically nothing, right? The problem is that the gaps aren't even. When you look down the barrel channel where the metal meets wood, you see 4" where the wood touches the metal, then 3" where there is a tiny gap, then another 2" where things touch again, then 6" of gap and so on. If it were uniform from one end to the other, then a gap like that wouldn't stand out, but since there is variation, it is hard to miss when you hold the gun close up, or at least it is for me. The finish on the gun is also overly shiny and the stock color doesn't quite look right. The Indians like to really polish things on a buffing wheel. At some point I intend on removing the barrel from the stock, sanding down the wood and refinishing it, roughing up the metal a little and seeing what I can do to clean up the inletting.
I haven't really wrung the gun out for accuracy yet, but if I can get decent groups out of it, I'll be satisfied with my purchase. For me, that's the real deciding factor. All the cosmetic details can be fixed and these muskets have enough of a track record for safety that I'm satisfied that I don't have a pipe bomb on my hands.
So far I just don't know about that one. People report being able to get 2" groups at 25 yards and 6" groups at 50, but I've only managed about 6" at 25 so far. I haven't really given it a fair shake yet though.