I tried, once. The UI was difficult, and I lost some money making some rookie mistakes. Kind of lost interest after that. Maybe they improved things? I think it certainly has potential, being one of the true decentralized places out there. I'll check it out again sometime soon. I would prefer to trade on there, actually. I've used Etherdelta for my ETH trades before CryptoKitties clogged it.
That site is pretty neat, I'll bookmark it, thanks!! But I the amount of usage is only part of the story though. I'm sure CryptoKitties is part of the reason ETH ranks so high currently, yet I don't know if that makes it the #1 crypto out there? Doge ranks pretty high too in this chart, for instance...
I do think it shows that STEEM/BTS handle a lot of transactions extremely well though, which bodes well for EOS if DPoS holds up in the long run!