No problems whatsoever, the brakes are perfect. I've taken it offroad several times, gone up to the mountains twice, highway driving, city traffic etc and the brakes feel great. The new handbrake is a big improvement and the AEV 2.5" lift kit has transformed the ride and handling.
I've also joined the Sydney Jeep Club and went on a run with them last weekend which was just brilliant. Scared myself a number of times, but I'm so glad I bought the jeep and stuck with it through the initial frustrations because it was just so good out on the trails.
One very happy JK owner here!