Hey PackRat,
Sorry for the late reply! You raise some really interesting points about the Alaskan vs. our Casita. We've thought it all through, including a visit to the factory to be inside a 7' CO that was near completion. Actually the difference in usable space and roominess is not quite as much as you might think. The interior length of the Casita is 14', minus 2' for the bathroom up front, and it is just over 6' wide. It's also a bit shorter. With the CO feature for the bed, we like the 7' Alaskan.
The truck was the question for us. We first considered the 6.5' CO on the assumption we could put it on an F150, but it was just way too close for comfort with the best capacity configuration we could get in an F150. So, we decided on the F250 and a 7'CO. When we bought the truck, there was a new F350 for a great price, so we went that way. Happy with that because of the extra margin for safety, ride, and durability.
We're originally from California, so the winterizing question is not something we dealt with previously. Have lived up in Southern Oregon for five years now and winterizing is second nature. I'll check it out with the Alaskan folks when we pick up the Alaskan late this spring, but am always seeking wisdom elsewhere.
Thanks for your comments and questions.
Happy camping.
Art