I have not used the Firestones but any tire that has ribbs that goes around the circumference of the tire you will find that the grooves in the road will grab the tire more...whether actual rain grooves or saw joints or even tar patches in the road. If you have ridden on ribbed tires before and you are used to it then its not an issue, but for new riders it will scare the crap out of you the first time you kit a groove in the road and the bike catches the groove. The K70 I have used and it is a good overall tire, far better handling then a full ribbed tire and it will wear better. The first thing I look for in a front tire is to make sure no grooves go around the tire, I like non radial patterns like are on modern sport bike, the more angled the grooves are or the more un uniform pattern the less affect the road surface will have on the bike itself. But again its all personal preference, I like newer patterns with more grip but some like ribbed old school patterns.