I had nothing but problems with J7's so I got some Formula's The One brakes. There is no other brake that can compare that I have used. Lot's o people like the Elixers tho.
my brother in law got juicy 7s and they drove me nuts trying to get them set up but since they've been set up they've been pretty good to him.
I've ridden a bike with The Ones but I can't really judge them since the owner probably went too high with his rotor size and they had too much power to have any kind of modulation in the conditions I tested in.
I really liked the lever feel of elixers when I tested them but didn't like that with a 8 inch rotor they didn't seem to have the power of my codes with a 6 inch. I'm hoping my franken brake will be the best of both worlds.