The speed at which they can get you qualified candidates for any skill set that you need.
There's no way to filter out specific skills or experience levels so it could be helpful if there were options like "I'm looking for someone with 5+ years of X". But overall I think we're getting what we want when we ask for them! It would also be nice to have some kind of contact info/website where people could go to apply directly instead of having to fill out an application through this platform. We've been able to find great talent quickly using their service and haven't really had issues since signing up.