It should be noted that the steering centerlink is for the most part related to Xterra's that are lifted. A stock Xterra shouldn't have steering issues for a long time, if at all.
Exhaust manifolds are covered for 60k under warranty.
I've found my truck to be extremely reliable, and I put it though a lot of abuse offroading. More than your typical consumer is ever going to expose their truck to. Like OffroadX mentined, it's a truck based SUV. Able to withstand more abuse than a car based SUV but less "refined" in terms of the sad luxury path SUV's have gone down.