Just as an anecdotal response from someone who does use the site, and quite a bit over the past year; roughly $30k in purchases and orders each, not only have I personally never had an issue with the way Reverb handled a situation, but their Safe Shipping has saved my ass multiple times with poorly packed items, or as a seller, sometimes shit happens.
Reverb has paid thousands of dollars out for safe shipping claims mostly to me for items the seller claims were damaged in transit, sometimes I could see damage to the box, sometimes not. Reverb didn't care, and they have also paid out claims on my behalf, always with a generous amount or an offer to pay what the maker quotes for the repair.
Packing skills have gotten so poor over the last ten years...I don't know how I would feel about buying or selling something not covered by their safe shipping. I have gotten items like a racked pair BLA preamps that had been knocked around a bit, but probably no significant damage other than tweaked ears and connecting plate...50% ($400) refund. I had a buyer hot-swap a 500 series module, frying it, reverb covered his repairs and it cost me nothing else.
I personally have nothing bad to say about Reverb. My only complaint is they are often too easy on the buyer, more than once the buyer has received a full refund and kept the item...never made sense to me.
PayPal can eat my butt and balls.