I saw a 1-star rating for this plugin with the reviewer calling it a scam. I was simply going to give it 5 stars and be done, but I decided to comment on the 1-star review: http://wordpress.org/support/topic/do-not-use-this-its-a-scam?replies=9#post-5710154.
This plugin is very-well thought through. They've done a solid job of creating a support forum and a client-log interface.
The plugin has been working exactly as advertised. The support is amongst the best I've encountered, and I've been doing WordPress superadmin multisite work for more years than I care to mention.