Here in SoCal there isn't much point in having dedicated sets of tires as it rarely dips below 45 in the winter. I'd wager 80% of my city driving is on roads with 45mph or 55mph+ posted limits so add around 10mph to keep up with the flow of traffic as A LOT of people are speed demons.
Once it comes time to replace the stock Pirelli tires I'll likely go with the new All Season Pilot Sport 4.
I've used the Vivvid Vinyl for a few projects with much success. As for the 20's, when you lower rotational mass, it goes a long way to making acceleration more... 'snappy'
