Welcome to our forum.
I've been using Doc's blanket for the past few months and I've been pretty pleased with the results. Though I haven't measured electric use, I will go out on a limb and say it definitely must be saving money. The 1/4" blanket does not bunch even with all jets on high.
Hey Tony, how difficult is that blanket to handle getting in and out of the tub? That was the only reason I hesitated with it. There's nothing worse than wrassling with a large piece of wet plastic in the winter.