Personal experience, I've found Kryptonite's CS top notch, so I always buy from them when possible.

I have both brands, and both have been good, however here in Texas the locks are not subjected to much in the way of temperature extremes. I do think Kryptonite's seem better made, but that is just me.

OnGuard does have some interesting pin tumbler keys on their low end cable locks. The cuts are on the side of the key similar to Mul-T-Lock keys, but without the telescoping pins. It doesn't affect pickability, but it does allow for more unique keys to be made, so less chance of one key opening someone else's lock.