I use the knot bobber stops too and thill floats. Trim excess line to keep interference with guides to the minimum. One of my buddies is famous for crossing someone else's line, getting tangled up and then he always says "You need to cut your line. I've got a slip bobber on." Never mind that the guy he crossed over does too.
It's cool to watch that bobber just slowly go down. Almost as cool as watching it start floating level. Or just moving. Fun way to fish. And can be very effective. Call me crazy but when I fish a slip bobber, I prefer 2 lb. mono.