Depends on the plane I want to fly.

4* 40, Twist and Somethin Extra = 15mph, crosswind doesn't matter.

The Twist and SSE do not want to land in winds much higher than 15mph plus I can stop them in mid air with throttle management, looks cool but in a gust, big pucker factor.

The 4* just slices right through. Up high it gets kicked around a bit but landings with a side slip are a breeze if you mix out the pitch coupling

CG Ultimate = 20mph without much of a crosswind. Reason is a BIG rudder. The thing wants to weather-vane big time in a 90 degree crosswind. Taxi is a trick in a 90 degree as it takes all of the rudder at 20mph just to keep it straight and that's on high rates.

Extra 300S = 20mph crosswind doesn't matter