I've been muzzloading for over 35 years here in PA. I'll always have a special place in my heart for T/C but you should hear all sides.
Started out fooling with a caplock pistol kit some one gave me when I was 17. I finshed that kit and got hooked. To hunt in my state at that time required a flintlock shooting a PRB, so I borrowed a T/C hawken built beautifully from a kit by a friend. Fit and finish was top shelf, the touch hole was well positioned and it shot like a dream. No one else here would buy anything but a T/C hawken and in those days, they did not make much else I bought me a used T/C Hawken.
The thing was not well taken care of but it was a T/C, my T/C and all I could afford. Shot PRB to a 3-5" group at 50 yards and I could usually put holes in a paper plate at 100 yds. She was hard to load the last few inches but she usually went off if I kept her clean and dry with a sharp flint in her jaws. I recall hunting in the rain but that rifle went off at the end of the day if I kept her dry.
She got me out in the woods after Christmas and kept hunting season alive for a couple more weeks and I loved everything about that gun, except when I was at the range. It fouled after a couple shots so I had to clean after 2 if I wanted to load a 3rd shot. Got 20-25 shots out of each flint 'cause the lock bashed 'em so badly. Still, I did her over completely, took out all the dings and scratches and reblued the barrel. I had her for about 5 years when T/C came out with the PA Hunter advertised with a 1:66" twist, .010 deep grooves and no shiney brass. Claimed it was a lot more accurate than the 1:48" hawken so I sold my hawken and bought a brand new PA Hunter. I could not make her shoot any better than the 1:48" hawken and she had a definite bad habit of not firing when a deer was in front of you. I had it happen to me 3 times and I actually saw it happen to another guy that had a PA Hunter on a drive one snowy Saturday. I knew how he felt when he hurled that gun into the back of his pickup!
Luckily, I only owned the PA Hunter for 15 years when fate felt sorry for me and the gun developed a crack in the wrist. I dutifully sent the stock to T/C for a replacement but they told me it "might take 6-8 months". I definitely got the idea that I might never see a replacement stock in my lifetime, so I acceped their offer to send me a hawken stock. They said my PA Hunter barrel would "drop right in" but my barrel was oct-round and did not match up well in the hawken stock. So T/C promised to send me a 1:66 hawken barrel if I sent them the PA Hunter barrel. The barrel they shipped had such a poorly positioned vent that I complained to T/C and sent the whole rifle to them again. They sent me a brand new hawken rifle with the touch hole well positioned, a new barrel and a new lock. I realized I was now back at the point I was 15 years ago. I no longer liked all the shiney brass and I was not about to go through another 15 years of problems and torture.
I got one of those "custom rifles" you talk about and I wish I could could have done it years ago. I sold the new T/C to help finance the custom gun and now I only own T/C percussion guns. I found over the years that T/C is committed to making percussion guns that do work. They are (were)commited to fast customer service but time and time again, they ship flintlocks that should not get out the door. Where I work, if we screw up and a customer is upset, we make sure he gets EXACTLY what he wants on the next shipment so he isn't more frustrated. These people do not do that - they often ship the next problem very quickly. I truly feel that T/C no longer cares about flintlocks, maybe they don't care about all traditional guns. The last 10 years, they seem to care more about the other types of guns they make. They discontinued most traditional guns and raised the price on the Hawken ridiculously high.
Be smart and buy yourself a used Hawken, even better a used Lyman GPR. There are so many out there that if you're careful, you can get a really good traditional gun for $2-3 hundred.
Finnwolf