How long can I expect a 2007 Ford F-250 superduty with a 6.0 diesel to last?

I'm looking at purchasing a 2007 Ford F-250 super duty with the 6.0 diesel in it. Current mileage is 154,000 and from what I can find on it has been serviced fairly well and was a texas truck. I only intend to use it to haul a 30' travel trailer a few times a year and maybe some local driving around town from time to time, but not really daily use. But my question is how reliable are they?

It's reliable, as a brand and a model, but every used vehicle is different. They are different in their current condition, how they've been driven, how well they've been maintained, and whether they have been wrecked in the past. Therefore, one 2007 F-250 could be a jewel, while another that looks just like it could be junk with serious hidden problems. So, when you find one you like, have it inspected by a professional mechanic BEFORE you buy. Otherwise, you risk making an expensive mistake.

The 6.0L has a laundry list of design flaws. By 2007 there had been some revisions, but it's not considered a particularly reliable engine until it's been bulletproofed.

Good for another 100,000 miles, if taken care of.