I have been running CTs now for 5 yrs or so on two different bikes. My F6B rides on a Kumho run flat Ecsta, and Valkyrie Interstate with a NEXEN.
I use Summer Tires with as few sipes as possible. My thinking is this..

For grip, we want as much solid rubber on the road as possible. IE: race cars run slicks for maximum traction. But of course they do not run in rain so the need for siping is a moot point.
Also with siping brings multiple tread blocks. Again, in my mind, that adds movement and a bit of wiggle to the tread.

I decided to read up on this a bit and found from most tire manufacturers have this to say re Winter tires

........................- the tread rubber of winter tires is considerably more flexible than that of all season and summer tires. That same pliable tread rubber that adds traction in winter will wear down quickly in warm temperatures. Summer and all-season tires are built to withstand warm temperatures, providing long wear life.
Decreased performance - In warm weather, winter tires won't provide the same handling capabilities as summer or all-season tires. Imagine if you needed to make a quick maneuver and your tires were soft and squishy. You won't get the crisp response from a winter tire in warm weather. Winter tires need that flexibilitity to handle ice and snow, but it's not as useful in warm weather.
The specialized compounds and tread designs of winter tires are not designed for optimal warm climate performance and wear...............


Sooo just to satisfy my need to know, why do many Car Tire users go with a Snow Tread. Am I missing out on something better by over thinking tread design?