Never had a problem with any TM lens system. I find it very straightforward and quick...more so than any other system. Nikon can be a bit of a PITA for me if moving very quickly. I love Canon old FD mounting. I can't stand Canon New FD mounting. The coolest thing about the BL system is how the lenses tighten themselves, and how they don't have any sort of interlock for removal! New FD does neither of those things.