I would get the nine lifes, but thats only because I have reno rockers right now and I want to try out a little stiffer rockered park ski by another brand, and the fact that my topsheets are utterly destroyed on my moments. (I dont mind chipping but this is BAD, it peels, ask dylan_, he can attest to it) The skis themselves are pretty durable though besides that, I've seen other moments without chipping as bad, and the bases and edges hasve taken a lot of abuse with no cracks or coreshots yet, so they still function 100% which is what matters I guess.
These 2 skis are all very different skis though, it all comes down to your riding style and how you want your skis to perform, but I'm sure they are all perfectly capable park sticks whatever your choice may be. Like dylan said check out liberty, I've been impressed by them quite a bit, also scott makes some pretty nice skis from what I hear, I've been drooling over some 184 P3's for a long long time. (which you can get on backcountry for like 300 right now, in any length)