I went from classic 99's and 101's, to 101 radial slims, and am currently on 99 conicals. I really like the radial slims, but a spot popped up a year ago and the ground is super crusty. It's almost like a comparing a road bike to a mountain bike. I went with the conicals because they roll over the crusty stuff a lot better. The spot is a super long, higher than average painted curb and 1 or 2 feet away from where you'd normally land, it's like they pored gravel over the blacktop before it cured. I call it the gauntlet, hahah. Radial slims would eventually slow you down to a halt if you rolled into it. Conical's get through it a lot more effectively.