I had an Xterra for years with no significant issues. It was the old platform, though, which dates back to the old hardbody from the 80s. Those were really reliable trucks. When the new version came out in '05, based on the same platform as the Titan (and Frontier and Pathfinder), I heard there were more issues. My folks and sister collectively put over a quarter million miles on a '96 Maxima and it never hand any substantial issues.
I'd definitely buy a Nissan again. Had the Titan XD Cummins been out, I would have cross shopped it against the Ram I bought. I would lean towards the Ram in that comparison because it's just a bit more truck for probably about the same price, but I definitely would have looked at it.