I've been investing with Groundfloor for a couple of years now. Honestly, I have no idea how well it's doing right now. I get a text every couple of days saying "Good news! An investment has been repaid and funds were depositing into your account."
I have the auto invest set up so that money just keeps getting reinvested in more notes.
From my understanding, most of the defaults end up getting paid back. The housing market is crazy right now so I expect that a lot of them will go into default and then get extended, but eventually get paid back.