Now, what i can say - YES, if you want to have perfect elastic solution, which you can customize to your needs, than use RedShop. I did not use VM anymore, and migrate from it to RS.
That is true - it needs time to prepare it to your needs. For luck, there is GREAT SUPPORT (paid but WORTH) - people who are ready to help you with simple and difficult problems.
I have also build a really powerfull Shop using Redshop.
With support there is no problems! and you can sell products ansd earn money :)
Additionally, there is a lot of ready plugins and modules thanks to which you can save time.
I am working on indywidual templates - thank to easy to use templates "framework".
I am VERY GLAD that i decided for RedShop.
Only thing which i would like to have it's better dokumentation (otherwise i have to take support time :) ).
Thank You RedShop Team!