I have several custom flintlocks, two long rifles of Lancaster lineage and a Jaeger. I got bit by the bug about 20 years ago and find that I pick up a flintlock in preference to any of my cap locks.
The trick is a quality lock. One rifle I have had a Russ Hamm lock and my may who left it to me used to have all sorts of ignition issues with it. the lock had been worked over by a local chap who is ver good at tuning locks, but it was still most unreliable. I bought an RPL drop in replacement lock from Track, had it tuned by a chap in Michigan and it has never been an issue since.
You definitely have to learn their quirks, but I have taken lots of rabbits and Kangas without two many misfires in all sorts of weather. Those pieces pictured are ver nice!

Cheers

Gordon