Alignment can make a lot of diff with steering effort. I went from 13's to 14" bmw bottlecaps for awhile the other year and didn't really notice any ill effects, the decreased wallowing from the shorter sidewall was nice. I don't think I'd go any larger/heavier willingly though.
If you care about a smooth ride I'd get rid of your MKI and get a vehicle built after 1995 or so.