I have been a member of WPMU since 2014. This party offers a beautiful set of plug-ins, which we regularly use. Although the plug-in is fantastic, we have mixed feelings about the support. The chat is good. You are helped quickly and they really do their best. However, when the second-line support is involved, a long wait usually occurs. Very annoying for us and our customers. In recent months we have regularly had problems with Appointment +. Given the stability of the plug-in, I would not recommend this. Hummingbird and Smush Pro are fantastic. Hopefully WPMU can deploy additional developers for second-line support.