I've used Braid exclusively for awhile to test it out. Now, I'm putting on a short Flouro leader on some for testing. Crankbaits sometimes tangle Braid around the trebles and cause a mess so I put on a 3' leader and really cleaned things up. I don't buy into the line-shy argument 'cause if the Bass won't bite because they see Braid, what about 2 treble hooks dangling, plus a bug plastic lip with a split ring, and how about that hard plastic crankbait that really does not swim like a minnow? I know confidence is big ang I've caught fish in every type lure made while using straight Braid.
I will always keep trying new methods and I like the leader idea for some applications, but mostly it's the right presentation to a fish that is actually where you are throwing.
To answer your question, I go 2' to 5' but no longer.