I have bought a 2005 Dbl Cab TRD Sport with Towing Package in August and is very nice.Doesn't have all the bells and whistles as the Tundra.
You can check out wwww.tundrasolutions.com and
www.toyotanation.com for 2005-2006 Tacoma owners forum and all the problems other owners have been experiencing.
Mileage seems to be an issue, I am getting 13MPG city and 20 MPG Hwy
whereas toyota claims 21mpg city/ 28 mpg hwy.
My truck is still fairly new so I would expect to get better gas mileage as it gets more miles on it.