Personally I find this to be a contentious topic here on RCGroups but not at the field. My home field welcomes e-power sailplanes, traditional string launch sailplanes and hand launch sailplanes. Heck we even welcomed a guy who wanted to try using a HobbyZone e-powered foam Super Cub to soar. We simply said that e-power rules apply which are power to altitude then its motor off until you land. He gave it a try but quickly realized that it made a poor soarer. He later went out and purchased a Radian.
I often wonder what would have happened if I had pushed him away by saying "No you cannot fly that here". That particular pilot has become a die hard sailplane guy and spent all last season flying a Radian and now wants to try a string launch sailplane.
We even hold monthly events\contests where both e-power and string launch planes compete side by side. No separate classes either, the string launch guys are going head to head with the e-power guys. The events are a blast. It can be done and it is very easy to incorporate both styles into one event. This coming season we will be holding a Man on Man event open to both e-power and string launch sailplanes. It too will be a blast.
Keep the faith.