To clarify, I ride a no suspension mtb and I switched out the tires to slightly narrower slicks (from 26/1.95 to 26/1.75). Also, the area I ride in is 100% flat.

I ride on urban/residential roads that are in notorious poor shape. Especially in the spring after a harsh winter, some streets I ride on are not really recognizable as streets anymore, but more a dried up riverbed.

I have also a bike with 700 tires, and the tires alone are for me a big reason why I don't use it much.