Even though I was a Joomla beginner, when I bought the extension, there was only very few troubles installing - and mostly due to my lack of understanding of Joomla.
Since then I have been working quite intense with several sites - all running on a Joomla Multisite installation - and there has been now trouble at all!!
Currently I run 8 slave-sites - each with dedicated database - on my main site. And I run on an apache-environment with virtual hosts and a Plesk administration panel. And everything just runs smooth and painless.
I had a single issue - but the support was exquisite - and the issue was solved immediately.
Besides that the documentation and forums works quite well.
I have still not tried the template feature - due to lack of time - but I am certainly looking forward to that.
Keep up the good work!!