Thoughts on proprietary firm payout process reliability

I've been thinking a lot lately about the actual reliability of payout processes from prop firms, beyond just the initial 'we pay x%'. Specifically, what are people's experiences with the consistency of the transfer initiation, how long funds are actually held, and if there's any noticeable slippage or increased fees during the withdrawal process itself? It's one thing to pass a challenge, another to consistently get paid without friction.