SyphonClient is not Key-Value-Observable for the isValid property. This will be fixed before release.
SyphonClient sometimes returns YES for isValid when it could return NO. This will be improved before release.
SyphonClient is not Key-Value-Observable for the hasNewFrame property. This will likely not change. If you need to observe this, use a new-frame handler instead.
SyphonServer is slow to publish frames when a SyphonClient with a new-frame handler is attached, or may stutter if a SyphonClient exists in an application which has hung (the blocking call will be publishFrameTexture:textureTarget:imageRegion:textureDimensions:flipped: or unbindAndPublish). This will be fixed before release.
The Framework Documentation mis-describes properties and shows internal versions of the header files. This will be fixed before release.