The first thing I would point out is very low fees for both the customer and seller.  The second thing would be the fact that accepting payments with crypto and Hive or CTP tokens in particular opens them up to a wider customer base since there are people who are unable to have bank accounts or credit cards but can use Hive and CTP tokens to make purchases. And the advantage for sellers of being able to get their money instantly and not have to wait 30, 60 or 90 days to get the money in their bank accounts. And they can't get shut down either. So, there's that too.  
I have experiences only from the customer side with CTP and Hive. Very positive experiences. For example, I paid for a subscription with Firepay and the owner flaked so I was having trouble getting a hold of him. Blain showed me the link in the receipt email and how to find my subscription in Firepay and cancel it from there. Very easy to do.