Well after our 208k mile 1999 Suburban was totaled by way of a tree falling on it in the driveway we "upgraded" to a 2004 Navigator with a mere 146,000 miles on it! I don't need to tell this crowd that going from a 99 (last year GMT400 platform as introduced in late 1980s) to a 2004 Navigator is a HUGE upgrade in almost every way.

When we bought it, one of the keys was that the air suspension was still intact and working correctly, however lots of minor issues came up due to age, and I'm pleased to report I've got virtually all of them resolved now, and with summer family trips around the corner, some getting done "just in time"

1) Replaced rear blend door actuator to stop "click click click" on rear air
2) reattached rear defrost wire with special epoxy
3) replaced leaky water pump (wasn't evident until about a month after purchase) and did serpentine belt at same time
4) Alignment and basic service from local FOMOCO dealer
5) Find factory chrome wheels from Craigslist, which also had 3 out of 4 good TPMS sensors, got one swapped out for a full set of functioning TPMS
6) Replace driver side seat bottom foam (it was totally falling apart and quite uncomfortable)
7) Resolve front a/c not coming through dash vents
8) Clean steering wheel contacts so that steering wheel controls work correctly
9) New Kumho Road Venture AT51 265/70 tires (32.6" overall diameter).
10) Install trailer brake controller

After all this, I think the only "feature" that doesn't work as intended is the door combination pad which I need to get into and clean..

about 6,000 miles and 6 months into ownership, and really do like it. Probably the most comfortable vehicle we've ever had for long trips etc; Got our newborn son home from the hospital safely during the only freak snowstorm of the season (~6" in North Carolina is epic! Auto 4x4/Advancetrac couldn't even tell there was snow on the ground).

Next up on the list is new spark plugs and boots, then off to PA towing our new 21' camper, then off to Florida in July for another family trip.

Ford got this beast right... Only negatives versus our Suburban are the tiny gas tank (Suburban had 44 gal vs 26 gal and similar fuel economy, so you had to take out a loan to fill the tank but only had to do so once every 600 miles or so), and the reduced space, but thanks to Ford's fold flat 3rd row the space hasn't been an issue yet.

Anyway, several of the issues I've resolved were MUCH easier thanks to this forum, and finding common issues, so just wanted to say thanks!