This question comes-up often. For me it's not the strait pull strength (pound test), it's the lack of stretch and the toughness of the line. As you said, I don't trust that braid doesn't effect the bite -- in many cases it does. So the leader takes care of that. I love the feel I have of what the bait is doing with braid, even with a couple of feet of floro. Also, what happens a lot, especially on a lake like Falcon, is a fish will get on the other side of a bush (or bushes) when many feet from the hook is getting abused. Nothing gives me confidence in those situations that some heavy braid does.

I've caught many big fish with 65lb braid and 30 or 40 lb floro that I'm pretty sure I would have lost with strait floro.

I use braid to flouro leader on my spinning set ups for better castibility and less memory and the fluorocarbon is less visable. You also get better sensitivity with briad and it's more visable to you, which is important when fishing lightly weighted or weightless plastics. I generally use a 4-6 ft leader.
I'll use braid to mono when i'm throwing a topwater bait or a trap in really thick grass, only about a 2 ft leader just so my hooks don't foul up with braid.

Hope this helps

I can fish anywhere from 15 pound to 30 pound test with one set up, that is with my 40 pound braid, I do not change my braid out but once a year at best, then I may just reverse the spool and have new braid, when I was using mono or fluro I would change my line out like every tournament, got expensive.

why do you use a smaller diameter main line "40lb braid" with a bigger diameter leader? Why wouldn't you use 65lb braid with 15lb leader? They're the same diameter.

I can fish anywhere from 15 pound to 30 pound test with one set up, that is with my 40 pound braid, I do not change my braid out but once a year at best, then I may just reverse the spool and have new braid, when I was using mono or fluro I would change my line out like every tournament, got expensive.