I'm entering my fifth winter on a pair of Nokian Hakkapeliitta W106s.
Just got the same tires a couple of weeks ago as my first studded tires.
My fourth winter I'd gotten a dynamo hub and couldn't afford a second matching wheelset, so I just rode the Nokians all winter, with occasional rides on my three-season bike. But boy, was I faster in the spring! Stronger too. I even bought a bike with a standard double. (None of that wimpy compact crap!) Up until then, all I'd ridden were triples.
I also have a dynamo hub so I will be riding them the entire winter.
I definitely agree with your sucking it up and HTFU attitude. I find the best training on the bike to be riding against a headwind. I mean hills are as good but there aren't any "mountains" around here. But I can ride straight into a strong headwind for 2 hours and it's like climbing a vertical mile.
In the end I think it doesn't matter how fast you go, just how hard you push the pedals. I guess that's really obvious but it just seems particularly obvious to me now that people train with power meters to increase their output.