It's an extraordinary achievement that after 7 years, Virtuemart remains, by many counts, on of the most popular open source e-commerce platform:
VirtueMart's strength is in its community support. The forums are excellent. If you're willing to Google your issue, you'll most likely find that someone has already resolved it in the forums. You may have to get your hands a little dirty with altering code, however if you're happy diving into the FTP and altering lines of code based on forum suggestions, then you can pretty much mold VirtueMart to your will.
VirtueMart comes with a lot of functionality as standard, and there are also a number of VirtueMart extensions floating about on the JED.
Shop Size: Medium to large
Default Look: 8/10
Support: Outsourced to third parties
Forum: 9/10. Very strong community
Documentation: 8/10. http://docs.virtuemart.net/manual.html
JED Reviews: 6/10.
Joomla 3.x: Yes
A shop size of 100+ items.
Shops that need a range of different features.
Beginner to mid-level developers. There's a large community, and the forums often have the answer to your questions.
Overhead for a tiny store.
No personalised support.