RC is thicker than Krown, which is why I switched. RC actually uses two different formulas, they use a thicker one for underbody areas and a thinner one (red color) for inner panels. The theory is that you want the thinner one in the panels where it can creep into the seems, and the thicker one for the underbody where it needs to resist the elements more without washing away.
The theory makes sense to me, which is why I've been using them. RC does drip...mostly the thinner inner panel stuff gets warms and runs out onto the ground. I park on the street for a day or so to let the worst run out. Then I put cardboard, or plastic or whatever is around on the driveway and park on that for a week or so. After that, it's usually fine.....It'll drip once and awhile afterwards, especially if the weather gets hot, but w/e. I care about my cars more than my driveway, and in the case of my asphalt driveway, a quick re-coat of sealer every couple of years tidies it up.