I have 4 turbo diesel trucks, and would like to add one to my little 1.3L powered tractor... it simply makes a diesel more efficient. With a turbo, you can use the same fuel, add more air (because of the turbo) and get more power. However, as has been pointed out, it's only at higher RPM ranges, and not likely to be of much use at low RPM ranges. That being said, the extra power at WOT during brush hogging would benefit me.
As to the added hardware, in a factory designed system, it should last longer than most home owner will run one. But short run times, and improper cool down after heavy use can hurt them. Once you train yourself to a new routine, you'd be fine. But they aren't rocket science, and are rebuildable. I just rebuilt one for my 7.3 powerstroke.