I almost hate my JJ's, because for what/where I ski, I need no other skis in my quiver. Sometimes I want something else, but with the JJ even charging down the groomers and surfing through the pow; there's just no need. I do however have a pair of ARG's too. They're super fun and I've ski'd them enough to the point where I don't need a foot of fresh to have fun with them, however, unless there's a good amount of pow, they're not fun to go fast on. The only time I take the ARG's is if it's really dumping or I want a challenge. If it's really dumping I bring both pairs, though.
Sorry for straying off topic, but yeah. I've never ski'd the NL, though I've heard great things about them. The JJ is just a one-ski mountain dominater.