Yes OKEx has a kickback commissions like Binance, the kickback is 10% while in Binance you could set up yourself from 0%-20%.
if you read the reddit/binance pages you will see that a lot of users have problems with them
What I read from some reddit users they are have a problem of waiting for the commissions, some are didn't know how it works since they're new. They didn't complaining if the kickback commissions is scam or any technical problems.