Honestly thought it was the ultimate upgrade for a cold climate. Reading about your regret makes me wonder if the slow warm-up time gets annoying. That constant background heat must really mess with your thermostat control too.
Warm-up lag is a real pain" - that's the perfect way to put it. I've got a buddy with one and he said the same thing. Takes forever to get the cabin warm on those single digit mornings. Trick is to run the engine for a couple minutes before you even turn the heat on full blast. Let the coolant get a head start. Otherwise you're just blowing cold air while the block heats up. Also helps to park facing into the sun if you can, takes a few minutes off the warmup time.