Welcome! I also got interested in the X because I like the original Pathfinders. Still have my '94 XE 4x4.
Since I have an 05 X, can't really help with your questions, other than to point out that the 04 X and the original Pathfinder (wd21) have pretty much the same set up regarding hubs/transfer case etc so should behave basically the same (no click from my Pathy's hubs, anyway). Couldn't tell from the post if you actully owned an old pathy or just liked 'em, though.
Anyway, welcome, and I'm sure you'll get some feedback from the other people here soon enough...