I prefer money, strongly. When you gamble with money, you are *risking* money for a chance to win money. It is always a losing proposition. But it’s not the same as *spending* the money. If I walk into a casino with a $50 bankroll, and I walk out of the casino an hour later with $40, then I’ve had a good night. Cause losing the the money will be okay for you but on the process that you won as will you'll enjoyed more than coins, you won't have to trade anything at the moment.
But gambling with coins will involves of spending more money on the play coins. Which have no value or gain at the moment (if they have value, they wouldn't be play coins, they do just be different kind of currency) So, you’re paying for the privilege of risking something of no value in the hopes of winning something of no value. That doesn’t even count as gambling anymore; that’s paying a fee for the privilege of keeping score on a random number generator. What's your own opinion towards this?
Well, ever since the inventory of cryptocurrency, and most online casinos having it integrated as a part of payment on the casinos monetary system, I did bet my balls that all those who have gamble online and have used crypto as a means of deposit and withdrawal, and also gambling, will prefer using crypto for gambling over fiat, I myself stopped gambling on offline casinos simply because I hate to gamble using fiat.
So, though I might not clearly understand what you mean by coins, I am assuming you mean crypto here, it might interest you to know that crypto gambling is not only faster and more convenient, but it also promote some level of privacy, much better and using fiat for gambling..
But again, I think it depends on which type of casino a players likes playing on, for online gamblers, I believe they will love to use crypto, offline gamblers will sure want to use fiat because fiat is more easily accessed offline than crypto.