I bought my 2012 Pro 4 X brand new from the dealership, I love it, best Vehicle I've ever owned. I just rolled up on 90,000 miles and the only mechanical issues I've had so far were two broken leaf springs. I cant complain about the maintenance cost because there have been almost None. If you Live in Maine you will understand we have a yearly safety inspection and the dealership always does mine and always passes with no issues. Tires, two new leaf springs and oil changes have been my only cost in the 90,000 miles. Quite a few of those miles have been off road. Its an awesome vehicle, to bad they don't import them in to the US any more.
I bought a 2012 xterra pro-4x with about 9k miles on it about 4 months ago. So far the car is extremely reliable, fun to drive and looks good. The only thing I do not like about the car is the cheap interior but even then it is made up for with comfortable leather seats and a great stereo. I also take it off roading and it is extremely good. Other jeeps can barely keep up with it. If you don't have fun in this car then you haven't been off-roading in it.
I have had my xterra for about 2 weeks (1000 miles now) and so far it has been a great vehicle. I sold my 2012 camaro because I wanted something simple and less extravagant. Plus, the camaro was giving me a headache of problems and I wanted to make the switch back to import. The gas mileage of the xterra is just ok, being able to take it on recreational trips will make up for this in the long run. Also, it feels solid and very secure to the road which I like, while being able to sit up high and in a comfortable position. I love how it rides like a truck, but does not knock you around too much.
I have only had my Pro 4X Xterra for a few days but so far so good. I bought it for $5300 off list over Labor Day at Bommarito Nissan in Hazelwood, MO. Nissan had some great incentives then. The Xterra drives great, smooth on the highway and solid when I go off road. Fit and finish seem to be good. I like the leather seats. The upgraded sound system is wonderful, much better than the one found on the S and X models. Too early to tell about gas mileage. It will probably be comparable to my 98 GMC Jimmy at around 18 overall. I considered going to a car based CUV for better mileage but none of those seemed to be up to the capabilities of the Xterra. I will write updates regularly.