These 2 pages break down what each of them offer.  I dont use either of them though, so I dont know how they differ,

https://proconnect.intuit.com/proseries/integrations/quick-collect/
https://proconnect.intuit.com/pay-by-refund/

Quick collect is at no cost for client, and small $15 charge to you (I just incorporate into fee).

pay by refund no cost to you and $ 50 or so charge to client.

Not positive about the charges for 2022, as I haven't offered in a couple of years, but I think quick collect is better, except if clients refund is taken. you have to collect fee from client