[spidertri]

My RE71Rs were certainly heat cycled out and quite worn, I'd gotten them new in spring 2019, hardly used them last year, and then used them up at several events this year. I had them flipped once a little past halfway through their life.

Remembering back to when they were new, I'd say the noise/comfort level driving to events is slightly in the RT660s favor.

The most apparent difference is the RT660 has much softer sidewalls, so much so that there is noticeable squirm when driving in a straight line and it feels like the tire wants to wander, takes a bit longer for the tire to take a set in a corner. Once I was used to that I adapted quickly and was able to push them hard.

They offer good audible feedback when getting to the limit. Mine wore nicely after the track day. I was warned that they might feather along the center rib but mine didn't do that at all.

Starting them at similar cold pressures that I ran the bridge stones at seemed to keep them happy.