The biggest differences, aside from the decentralized exchange, are ease of use and scalability. You make transfers to account names and they are basically instant. It is super fast and easy to move BTS around. The blockchain also currently handles 3000 transactions per second and can scale to 100,000 TPS. There is a major project underway that is using the Bitshares blockchain for point of sale systems to capitalize on the blockchain transaction capacity. So in summary, it's faster, simpler and scales better but is not a competitor to Bitcoin. Bitcoin seems to have been design primarily as a store of value, like gold, and Bitshares is more of a broad financial platform.