One of the dealers I visited last weekend (Caldera?) showed a document from the California Dept. of Energy. Apparently, all hot tubs sold in California are REQUIRED to be tested for R-value. The document listed hot tubs by manufacturer, and showed an R-value for each.
I have not bothered to search for the same information online, but apparently it is available. The two tubs we were considering were the one offered by that dealer (R30), and the Arctic Spa Yukon (R28). We have since decided on the Yukon, with the deciding factor being the ability to service the underneath of the tub without scooping out foam and replacing it. The tub will be put on the ground, and surrounded by a 16" high existing deck. The Yukon sits high enough that I can service it through the panels without having to remove any decking, which is important given the specifics of our deck.
Oh, and we live in Kitchener, so I know all about the cold climate.
BTW, I was surprised at how low Beachcomber scored. I believe they were R22. The tub we have now is a Beachcomber, but we inherited it from the Previous Owners of the house, and they let it sit dry for a number of years. As a result, we have had constant issues with leaks. To me, it isn't worth the hassle of pulling the tub out, turning it on it's side, scooping out all the foam, trying to figure out where the leak(s) is/are, changing out all the piping, putting it back, filling and running it for a while to determine that it's fixed (or not), emptying it and putting it back up on it's side, sprayfoaming it, then putting it back down in position and filling it again. Not, at least, for a 12 year old tub...
ChrisP in Kitchener