I love my Armada. It does have a few things that need to be taken care of under warranty though (being a '04).... Don't even consider an '04, go for the '05 or '06 when it comes out. They fixed a lot of little "stupid things".
As for mileage, I get about 15 around town, up to 18 or 19 on the fwy if I go "easy".
Mine has the captains seats in row #2 so it
only holds 7 instead of 8.
The 5.6 L engine rocks. It seriously goes like a bat out of hell.
Oh, depending on what features you like, you may lean towards the "LE". Personally I'd chose the Offroad edition, but I found mine at auction for cheap so I couldn't pass it up.