In reading through this thread, I have a couple comments. I think you will appreciate the closet slide, no matter what it adds to weight. A 3/4t truck will have no problem with this size unit. Your only problem would be serious mountains and the gas engine. Those trucks setting on the side with heating problems mentioned above won't be restricted to 1/2t, it's the gas engine and accompaning auto trans. In my previous tow setup, I had the most problems with transmission temperatures. You should be okay as long as you don't try to run up them hills with the cruise set on 70.
I also agree that a 3k+ lb boat might be a bit much. I need to tow a 1k lb atv, and wanted an enclosed trailer bad, but figured the weight would be to much. I settled on an aluminum utility trailer that weighs 400 lbs. My total trailer now will weigh about 1500 lbs, with 170 lb tongue weight.
We enjoy our Signature Ultra light. With the light weight construction, you do give up some quality, but it's still a good bang for your buck. It is not insulated real well. We've only used it so far where heat was required rather than the air When it comes time, I think we'll be glad we have the 15k air. It came with the Reese Revolution hitch, and with my sb, I can turn as sharp as I want.
2012 Signature 8285WS
2010 Ram 2500 w/Cummins