I have just cancelled my subs.
1: Support is non existent apart from other members
2: Plugins are out of date with no intention of improving them.
3: Notification plugin is advertising spam
There are many more reasons for leaving WPMUDEV but it seems to me that the owners are just sitting back watching the subscriptions roll in.
I forgot to add that a good portion of the plug-ins should be in beta and not used on a production site.