Very comprehensive. Multisites with all the bells and whistles. This extension provides lots of possibilities.
Ease of use
It does have a learning curve. But this is to be expected for an extension of this kind. It solves a complex problem in a complex CMS.
A forum, in which the developer responds personally, E-Mail and paid support. He knows what he's talking about and is very professional.
Documentation is very thorough and, in fact, is available in English. The PDF has 99 pages. Plus more in the forums and the website.
Value for money
Very good. Once it's setup you hardly ever need to touch it again, except maybe for configuration changes.