Filters workout - what made you decide on OpenCart?

I'm coming out with a super-secret new website with OC1551 (shhh!) and want to give the new product filters feature a good workout so people can really try it out. My customers will be comparing (filtering) OpenCart to other carts like osCommerce, VirtueMart, Magento, Loaded Commerce, blah-dee-blah.

SO to create the most useful filters - can you tell me what features of OpenCart made you choose it for your cart? What was the clincher for you? Here are some ideas:

Ajax image management
Auto image resize
B to C power (business to consumer)
Best for beginners
Easy to use
Extensions - many available
Extensions - kept up to date
Extensions - easily searchable
Fun factor - farfegneugen
Good forum
Multi-store feature
Modern themes available

...more?

Thanks in advance!
merry

Multistores was the cincher for me. That and opensource, ability to edit and customize everything.