"cheater slicks"

I have experience with the Nitto and the M/T drag radials. Based on a bunch of time slips, (but no actual same day comparisons) my impression is the Nittos are slightly softer, and maybe hook out of the hole a little better, but the M/T's work better on a decently prepped track. I can't get much more than 5000 miles out of either one, but I'm not really trying to either, if you get my drift... :-)
I don't think a half inch narrower wheel will make any difference at all.