Did you not get an answer in the forums, or were you not able to register? You can use the little mini-contact form on any page (except the homepage) on foxycart.com to ask questions if you’d like.
Here’s a photography website using FoxyCart:
http://parishtoparish.com/
Our userbase doesn’t compare to something like ZenCart or MODx or anything that’s been around for years, but it’s growing significantly every day. I apologize that it doesn’t look like that. We’re working on improving our featured sites functionality to show at least a fraction of the stores that are live using FoxyCart, rather than the same 3 that have been there forever. Sorry about that.
Feel free to ask questions via PM, the FoxyCart forum, or using the contact form on the website.