I had a positive experience with Redfin, but honestly feel like even with the refund check, I still overpayed for their contribution.

I shopped online, went to open houses on my own, and Redfin basically just contacted the seller on my behalf to present an offer. I'd be shocked if my agent did more than a few hours total work over the entire duration of the sale – though I liked him a lot, and he was super responsive the few times I needed him.