LZs are a lot heavier, and people seem to like the case itself a little better, but GONs latest PCB, the NerD.2 is probably one of the top 3 to ever come out of Korea. (My personal top 3 list is 356 CL, NerD.2, and KMAC 2, in that order)
Kustoms are generally regarded as the best gaming keyboards. They also attract quite a bit of attention at LANs, if that's what you're into. You can put reds in your Kustom and literally become a god. *
keyboards are not a substitute for actual skillI think GON's boards work with OS X, but you can check his
question thread to make sure.
Depends on what keycaps you put on them. Both boards come with feet for the case that you can install if you wish.