I've used braid exclusively in lake trolling from the kayak this summer. 4-8lb diameter, 10-30lb test. I've only used leaders when fishing for stripers (unsuccessfully so far - maybe its the leaders!). Usually just braid to a snap, snap to a crankbait. Most of the water around here is discolored, so I don't feel too bad about the visibility of the braid or the snap. I would feel different in clearer lakes.
I do set the drag extra light when trolling, in case I do hang up. The only mishap I've had was a hangup with a low capacity casting reel - it spooled quickly and popped the backing knot before I even knew it was hung. Lost a spool of good braid and the crankbait. The audible drag on the spinning reels helps avoid this. The braid is strong enough not to pop and I've gotten everything else back.
I'm doing pretty long drops behind the boat - 50-75 yards trying to maximize depth on the crankbaits. The small diameter of braid should be helping me back there, plus leaving extra line on the spool in case I do hang up or hang into a drag puller.
For knots I like palomar for braid to metal (hook, snap, split ring, swivel), and a j-knot for braid to leader. They're the easiest for me to tie.
The negatives are the way it whips around in the wind. I get a little frustrated with it looping around rod tips when its slack, and its great at finding the trebles, but I think it pays for itself in the long run.