I have been playing with Virtuemart for a few months and I have only recently gone live with my first shop.
With in a month I have managed to get a few sales and I am now busy working on traffic.
Only real issue I have had was getting some proper checkout templates. I ended up using templates from a template site that was modifiable to my taste.
Would be nice to see a add on what gives you the capability to work with multiple orders at once and to do shipment track.
But all and all I very,very happy with Virtuemart!!!