I've had one (Lyman, not TC)on my GP flintlock for the last four months or so. I love it. I'ts about the only iron sight I can use with confidenceout to 75 and 100 yards. I think the Lyman's adjustments are more user friendly than TCs, but the results should be the same.

Here's my best (nottypical)100 yard 5-shottarget using that sight (wish I hadn't blown that 5th. shot [:@]). Pretty dang good for bi-focal eyes. My more typical 100 yard group is more like 5 inches, but I can pretty regularly keep all five shots on that 3" bullat 75 yards with the Lyman peep.