I replaced the front 1157NA, the rear 7440 and 7443 along with 3 interior lights. I chose the so called super bright ones but after seeing OEM LEDs on other cars, mine don’t appear to be as bright - at least not as bright as incandescent bulbs. In order to stop the rapid blinking issue, I purchased an aftermarket electronic flasher from autolumination.com. They sell a direct replacement for the 2008 Scion and other Toyota models. http://autolumination.com/equalizers.htm, part number 8 pin FH-0435 FH-0436 81980-50030 06500-4650. The flasher is more versatile than load resisters, because you can mix LEDs and incandescents as long as you don't exceed the total wattage - 175 watts.
Note: The exterior light flash confirmation does not work (when you lock the doors with the remote). It may be related to reduced current flow through the electronic flasher. I understand there is about 15 watts per filament in a regular bulb versus probably less than 1 watt is most LEDs. I use 3 W LEDs which is only 1/5 the wattage of a typical bulb. To increase the brightness, I am considering customizing my tail lights with more LEDs.