On fixed-price projects I've generally worked for 50% up-front, which I believe is more or less standard for software development-related freelancing. I'll sometimes ask for less than 50% if the budget is high.
Is up-front payment still a standard when escrow is available, or does escrow entirely replace the up-front system? Please note I am not asking whether up-front payment is standard in general or what percentage to charge, just whether it's still a standard when escrow is used for the payments.