had my '08 v8 4x4 since early nov '10 and i love it. the gas mileage sucks (i came from a v6 car that could get 28 hwy), but i still love it.
i got it with 23k on it and i just hit 36k. i've taken it to colorado for a snowboarding trip with two other adults and one child. everything -barely- fit (including snowboards) without using a roof/trailer rack. next time i will have a rack to at least put the snowboards on since they took up the most room. i think we got ~18-19mpg. it did wonderfully in the light/medium snowy roads, even with stock tires (bfg long trail ms).
the 2wd-auto-4wdH-4wdL option is freakin awesome for someone like me who likes to get the rear end out (with traction control off) a little every now and then. 2wd is like any other rwd sports car. it can get real squirrely -real- fast. however the auto mode is fantastic for people like me. doing a left hand turn from a stop sign in the rain with auto will let the rear start to slide out, but engages the front at just the right moment to pull you out before you hit that 'oh crap i'm going to lose it' point. it does take some getting used to, but once you get it, it's a blast. the girlfriend doesn't like it too much though

(on a side note i'd say i'm pretty responsible with horsing around, i don't do it when there are other cars near) otherwise with traction control on i hardly take it out of 2wd.
i love love love the power the engine puts out. this is also why my regular city gas mileage is so crappy though, i have a hard time keeping my foot out of the accelerator. but every time i punch it, i get a smile on my face.
i did have a valve related to the egr system go bad, but it was before i hit 36k. i also opted for the 100k nissan extended warranty, just in case.
i have noticed that the front rotors are starting to warp. i get the shakes in the steering wheel when braking, but the early warping may be attributed to my aggressive driving style.
you do get the 'tire walk' when going over hard bumps. this is a body on frame construction, so it's more rigid/rugged than other suv's. handling is washy at higher speeds, but come on, this is a 6500lb suv, not a race car.
ac seems fine to me (we've had 12+ days of over 100F temps here in dallas), but it seems if you have the rear ac on, the front ac doesn't cool -as- quickly. i'm guessing the rear uses the same freon lines as the front, and maybe the ac radiator can't handle both at the same time when both are on full blast?
the heated steering wheel is kind of nice in the winter, but it seems to surge up to 100F when it's first on. then it pulses up to about 80F after that.
i like that the 2nd row seats recline a little. i have no use for the 3rd row at all. i do keep the 3rd row up so i can keep my laptop bag from sliding around everywhere, but it's -hella- annoying that you have to put the 2nd row seats in their upright positions in order to put the 3rd row seats down. after they're down the 2nd row can recline again, until you want to put the 3rd row back up again.
ok, i think that's it! hope this helps if it's not too late.