I think the pratt on the 752 comes off wing about 6-7 k/hrs. They supposedly save a bit of fuel but the overhaul cost's make them less preferred, heard they are not fun to work on as well. We have been putting 752-f's into service like crazy and I think we just put our first pratt powered one in. Suppose I shall find out for myself soon enough. The reliabiity on the rolls has been pretty good, I like looking at them on an engine stand, they just look soo clean as compared to a cf6, less monkeymotion.