I personally wouldn't recommend anyone use etherdelta if you using it for big amount of money use at your own risk, the site is extremely unstable, orders get stuck , sells gets stuck, buy orders get stuck and just vanish without a trace.... Nothing seem to ever work correctly. Owner of site has not fixed any of those issues. The platform is a traders nightmare...
If you want to make instant order try to increase gas price per transaction. Otherwise "first come first serve" rule works on decentralised exchanges. Etherdelta is good exchange and smart traders can make decent profit there.