I love my xterra! I would fully recommend this suv to anyone. I bought mine used in 2012 with 140k miles on it (highway miles). I have put over 10,000
on it since and we're still going strong. When I purchased the vehicle I had it tuned up and old hoses replaced, but only because I was unsure of how long how it had been since it was serviced, since it was pre-owned. The only thing I could complain about is the poor gas mileage that comes with driving any SUV; however, it gets better gas mileage than most other SUV's i've driven. Over all I am happy with my xterra's performance and would fully recommend it to anyone!
Favorite features would be the amount of power sockets in the car. I am able to plug in my iPod, cell phone and GPS with no problem. I also love the option of keyless entry OR you can unlock all the car doors by inserting the key into the door and turning twice. Also the car is small on the outside, but very roomy on the inside.
The only improvement I could think of would be gas mileage.