How good is Marketpress for large stores?

Hi,

I've started using Marketpress for a couple of clients with smaller store and I'm really happy with it. It does the job simply and effectively.

I was wondering if any had had experience with large stores. I'm evaluating it's possible use for a store with around 500 products and over 1000 SKUs and very probably going to double over time.

Has any one got some feedback on how easy to use the plugin is for this size or larger?

thanks!