My dad bought a 2000 model F150 5.4 4x2 in 1999. I am highly impressed with the torque it makes. It's not as "fast" as the GM 5.3 of it's day but it's a truck that has been used its entire life of 243,000 miles pulling race cars, tractors, and mowers (and everything in between), and it's never once given any major problem. IAC at 125,000, and one coil at 200k.
I bought an 03 lightning in 05 and drove the fire out of it. Raced it at many different tracks around the SE USA (drag racing), pulled the race car to/from different tracks, unhook, run the truck in the street class and run the race car in the no electronics (bracket) class. Every weekend for 7 1/2 years. In between races, it went to 46 of the lower 48 states. I traded it in '13 for an 03 F250 diesel (7.3); mainly because I bought an enclosed and pulling it with a lightning was just wrong. That and the Lightning had a ton of miles on it. Still have the old clattering 7.3.
Brother has an '05 F150, 5.4. 418,000 miles, had to put a transmission in it at 320k about 2 years after he bought it but other than that it's been great. Phasers are noisy. Plugs have been changed several times as well as coils twice. He has all the maintenance records from the PO as well.
The 5.4 is impressive for it's torque. We had an '04 at work for a shop truck and I loved it for pulling tractors around; it pulls like a diesel (well almost). It liked gas, though. Boss traded it straight up for a '07 silverado 3500 dually with a duramax which cost us right close to $20,000 in engine and transmission (only) repairs. It's gone now, replaced by a 08 silverado dually with a 6.0 which is also falling apart. Both the 07 and now the 08 both had/have 122,000 miles on 'em. But the good thing about the 08 is that it's a LOT cheaper to fix but it doesn't have anywhere near the torque down low that the 5.4 Ford did-NOWHERE near.