I switched from a 60 profile BT010 to a 70 section Diablo. For me, the front felt a little more planted in the corners. The steering, or speed of it anyhow, felt no different. The one thing I do have now is chicken strips on the front, whereas on the 60 I was off the edge.
The other thing to take into account is that a "quick" profile, like 207R for instance, even in a 70 section would still feel quicker than a more sedate 60, due to the actual shape of the tyre itself.
It's all down to personal preference at the end of the day but I'll be sticking with the 70 section Diablo for now.
