No, I'm not opening up a comparison debate about these two lock ignitions. Heck, like many of you out there, I use them both, and enjoy them both...
Fact is, the first ML I ever shot was a flintlock back in the early/mid '70's (can't remember the exact year for sure) but it belonged to one of our NCO's who kept one in my Arms Room while stationed at Ft. Riley. I only shot it a couple times with him and it was enough to get me hooked. When I ETS'd in June of '77, one of the first things I did was get a couple CVA caplock rifle kits and have been shooting muzzleloading firearm's faithfully since then.
Now I didn't get back to the flintlock ignition until about 20 years ago (or there abouts) anyway, even though I have rifles in both ignitions - over the last six to eight years I've been straying further away from the caplock simply because of the price of caps. They're getting more expensive all the time. Now that's not to say flints haven't gone up because they have as well... However,,, the one thing I
can do with a flintlock that I
can't do with a caplock, is pick up a piece of flint or chert off the ground and make a temporary workable rock to shave metal sparks off my frizzen into my pan of prime and set off my charge.
I think weighing the options of ignition should play a part in decision making (for me) of what ignition to go with. Obviously the flintlock wins out in the above mentioned... However,,, the caplock is very handy in as much as you don't need to prime a pan from your powder horn (or priming horn)... Simply cap the nipple from a brass cap holder or leather cap holder, and you're good to go.
As far as humidity with both systems drawing moister, I personally believe they are about even once that first charge goes off in high humidity. Both systems seem to require some tender loving care between shots on humid days.
Flintching? Sure, that exist for a while with the flintlock but the shooter soon shoots his/her way through that and it's no longer a problem. With the caplock we don't worry about such things.
Follow through? Well, both ignition system's require follow through in my opinion. The flintlock (again IMHO) may need just a bit more,,, but that could just be a mental thing? In any event follow through with any firearm system should be second nature, and with the both the flint and cap locks I think one should always try to use the same amount of time.
Cleanup? I found that it takes the same amount of time for both the cap and flint locks.
Anyway, I've rambled on enough and perhaps this post belongs up in the Campfire board, but after all this typing I don't want to risk loosing it, by moving it now. Also, if some of you soon to be builders were on the fence about what to build, (flint or cap), this might be of some assistance.
I will end by saying this one last thing; Flintlock (for me) have always been way more fun to shoot, but go with what you like...