I have been using virtuemart for years and the update to 2.0 is a good one. I like the fact that everything is customizable and prefer it over Prestashop and (maybe) Magento. But this is because it is native to me after all the times I have used it.
Only 1 big point of improvement: multishop compatibility. Now it needs a hack-a-round to do this and with multiple shops selling partially the same products it is a necessity for my inventory.