AFAIK, they're almost instant.
But money orders have to go through the mail, which can take a few days. What are some that use cash like western union that don't require the money to go through the mail?
I've tested it before and the transfer was almost instant. I only have to wait for a few minutes so that I can track the remittance that I'm about to get.
I have no idea, I don't usually use remittance these days because transferring online is easier with the help of cryptocurrencies.