I think UP is the only one so far to order the EMD H engine, & they have all been through one modification after another trying to make them work mor reliably. I've only been around one of them, we had it on a train out of KC last year. No idea what it was doing on BNSF. It worked fine for the 6 hours I used it. I heard the old 2 cycle design they've used since the 40's will no longer be EPA certified, & they have to make this new 4 cycle work sooner or later. Haven't seen any of GE's new ones yet, I think CSX has a bunch of them alleady. I have no idea how many hours the old SD's have on them, but none of them have many original parts on them except most of the frame. On BNSF, I've punched around on some of the on board computers to get life time mileage totals on newer units, and they're getting about 130,000 a year on most of the road units. Most of the big class 1 roads are letting UP be the guinea pig for the H engines.