Very cool!
The main feature I use is the 'One to many' matches. That's in the "Analyze your data" section, and at the top of the "DNA Raw Data" sub-section. It's basically exactly like the list of matches that AncestryDNA gives me.
The first person on MY list happens to be someone who was adopted. I spotted her on my AncestryDNA list, and was able to help her figure out who both her birth parents were. It's really helpful, I imagine, if some biological relative who's good at this spots you, and helps out, because they already can tell what family you belong to, at least on one side. In my case, I happened to have interviewed her biological grandmother for genealogy, so I had some "inside info" about who all the living relatives were, and their ages, and that narrowed her bio-dad down to ONE guy. It sounds like that kind of resource is rare, though.
I didn't get onto GEDmatch until a few months later, but when I did hers was the first name I saw!
Best of luck, sir!