I think the aluminum F150 weighs the same as the Colorado.
The MPG issue is probably true too.
I'm probably going to be looking for a first gen Colorado. I would love to find a regular cab with 4WD, but they seem to be unicorns. I talked to Remco (or Superior Drivelines), and for $1000 I can get a complete driveshaft disconnect for a 2WD. A regular cab first generation is pretty light. Especially if 2WD.
Back to the new gen, I hope they figure out the transfer case issue. There is a need for a reasonably light pickup dinghy IMO. Supposedly there will be a new Ford Ranger in the next year or so? But will it be towable, who knows.