I had a set of Goodyear Eagle GTII tires when I had Roush 20" wheels. It was ok at best on the road and horrible during the rain.
The Nittos have a great reputation, but they're more of a summer tire. There might be a better option for your needs, but I disagree with the guy saying the 420s are no good.

 

Nittos can't be "cheap" . . . now offbrand tires, those are cheap!

 

yea I have never heard really anything bad about nittos. might not be the best out there but for the money seems to be a good tire.