Prop Firm Infrastructure: Broker Choice & Payout Friction

Curious to hear about others' experiences navigating the infrastructure side of various prop firms. I've been with a couple now and one consistent pain point seems to be the underlying broker or payment processor they use, particularly around withdrawal times and associated fees. It's one thing to hit targets, but if getting funded capital out feels like pulling teeth, it really erodes confidence.

Specifically, has anyone noticed a significant difference in effective spreads or liquidity when trading with prop firms that use different primary brokers (e.g., one that routes through a major ECN vs. another using a less transparent model)? And on the payout side, beyond the initial KYB which is standard, what kind of friction have you encountered with subsequent withdrawals? Are certain PSPs consistently faster or more reliable, or is it just the luck of the draw with the firm itself? I'm not looking for specific recommendations for firms, but more about the process and common pitfalls on the backend. This is crucial for evaluating a firm beyond just their challenge rules.