Since this is a free extension, you might expect a poor support history, and indeed, this is true. The developing company seems to be under the impression that you can release software for free, and only provide paid support. There is an online forum, and simple questions are answered therein, however anything complicated is deferred to paid support.
To that end, I have posted multiple times about requesting support which I will pay for, and I have sent the company emails, and submitted the contact form on the site. I have not received ANY reply's to these messages. It's as if these messages don't ever make it to the company.
Summary: If you need Joomla 1.6 or 1.7 and a basic store, this will be perfect.
If you need something non standard, stick with Virtuemart.