It depends on what you consider to be slow.
What we do see is when the golden image cannot reach the Appvolumes server and the service is started that logon is very very slow (up to 2 minutes to log in) because the agent tries to reach the server. This can be changed using a reg key but because we only have this issue when creating our packaging machine I don't care that much.
Other than that, Appvolumes is a filter driver that checks changes being made to the file system. So every action that is being executed will be monitored and checked by Appvolumes. It also depends on your machine. I would not suggest using a 1 vCPU machine with Appvolumes as the filter driver uses 1 during logon.