I've got the 1999.5 SD now. Had a F150 I retired last year after 26 years of service. I had a Ranger that I ran for 14 years. Had LTD and Torino wagons and assorted other Fords. I have had my share of GM's, Buick (2), Olds (5), Caddies (1), Pontiacs (3), Chevy (2), plus several Dodge Durango's. Curently have a Suburban, Chrysler 300M, and Toyota in the stable with a Pontiac Firebird in storage. With the total accumulated vehicles I have owned and driven, I can honestly say there is really no difference in function and reliability as long as the vehicles are maintained on regular basis. I do have a preference for Ford Trucks and would have had an X instead of 'burban had it not been for the 2004 6.0h!
All that given, I would not buy a Chevy Truck just based upon the looks alone - one ugly truck, plus I am fond of a solid front axle.