I've basically kept track of everything that's happened with my truck since I received it new in November of '02.
Following is a list of the problems encountered:
Aug '04 - 44,000 km/~30,000 miles - Air Bag Light "on" - traced to moisture/corrosion in underseat wiring per TSB on problem - this problem recurred a few more times - cleaning up the connnectors solved the problem each time
Jul '05 - 80,000 km/~50,000 miles - replaced alternator
Oct '05 - 90,000 km/~55,000 miles - wiring problem in transfer case
Jun '06 - 130,000 km/~80,000 miles - vacuum hose elbow split - front of engine where it was rubbing against upper rad hose
Jul '06 - 140,000 km/~86,000 miles - new fan clutch
May '07 - 200,000 km/~125,000 miles - broken rear leaf springs - a middle spring from each side split right at the axle
Jul '07 - 210,000 km/~130,000 miles - passenger side power door lock actuator replaced - driver's side actuator is acting up intermittently, but is still working to this day, though sometimes I have to press a couple of times (either on the remote or door buttons) before it opens/closes
Sep '07 - 225,000 km/~140,000 miles - starter and fuel pump relays replaced
Oct '07 - 230,000 km/~145,000 miles - brake pedal/light switch replaced
Oct '07 - 235,000 km/~150,000 miles - parking brake cables (to each rear drum) replaced (seized on passenger side)
Dec '07 - 245,000 km/~155,000 miles - wiper relay replaced (after this, I just replaced the rest of the relays in the underhood fuse box)
Sep '08 - 280,000 km/~175,000 miles - wiper motor replaced
Nov '08 - 285.000 km/~180,000 miles - thermostat and gasket replaced
Jan '09 - 295,000 km/~185,000 miles - alternator (2nd time) and battery (original) replaced
(I've rounded off the km, and the conversions from km to miles is approximate.)
All this in addition to the specified regular maintenance (or better) as per manufacturer's schedule for fluid changes, plugs, wires, belts etc., and replacement of regular wearing parts such as brakes and associated hardware, rotors/drums, bulbs, and so on.
On my vehicle, I would say that there was (maybe still is) a problem with the relays - just today I had to replace another fuel pump relay (well, it has been about -10 to -25 degrees C up here lately - I think it still translates to the -5 Fahrenheit range or thereabouts) - funny because the replacements were all OEM Ford products.
Other problems: the a/c was acting up this past summer - I'm probably looking at replacing the compressor this coming spring/summer; the driver's side power window doesn't close completely - looks like the winder regulator has some worn teeth at the top of its travel; the driver's side power door lock actuator could give out anytime - though it has been holding its own since problems were noted with it.
In all, I would have to say that my truck has been quite reliable - some of the "problems" are just normal wear items, or due to individual usage factors (e.g. the cracked rear springs might likely be the result of a series of quite heavy loads that that were being carried during that time).
Hope this is of some help in your survey.