I am working on a project for an electronic mall (like ebay or etsy), and am inclined to go with Magento, primarily for its EAV database layout, which I would expect to make it scalable for large amounts of regularly changing inventory. But would also be very slow and I don't see Magento being used in this situation. Although I could throw additional hardware at this to speed this up, there is probably a limit to that. Any other options that would be better for this situation?
I'm not particularly familiar with Magento, but as a database guy it seems to me that the speed of ANY shopping cart these days has more to do with proper indexing of the database than the cart itself.
A properly indexed database would show millions of products just as quickly as hundreds.
I have used 'vpasp' it's an amazing cart. I've gone from nothing to doing over $2m a year with it and it can handle much more. I love it. It may or may not work for what you want but i'd take a look at it for sure.