I've tried everything Korgian EXCEPT the N series, but I suspect they're in line w/previous offerings. 1st, all keyboards have
SOME clickiness. My 01/Wfd does clunk a bit, but that's part of the gig. I'm a bit heavy-handed, so I just live with it. The alternative is to buy a specific controller, which can be expensive. I like the Korg feel as compared to most other 'boards, so hey ho.
I've found virtually NO organs that sound good out of the box, unless they were already "combis" to begin with. That's just synths; you have to stack a couple of organs together to get near the weight of a real B-3, for instance. That's the tradeoff, which I'm HAPPY to accept. Try layering 1, then 2, etc. and see how you like it. The N series shouldn't be too different, in that layering patches is fairly simple. Korg makes this easier than most other companies do.
Where ANY kind of "thinness" is concerned, go for the FX 1st. The reviews indicated that N effects were specially set up with ease of use in mind, so I'd say devoting some extra time to cracking them would be rewarding. I run my Proteus through an Alesis FX box and it makes all the diference in the world.
Sound quality is pretty subjective; the one area where Korg "fails" is in the techno/industrial arena. If that's part of your complaint, try these sites for patches:
With a little effort, you can usually assemble a set or 2 that ring your chimes. I had to sweat a little in doing so, but it made the 'board more satisfying in the end.