They do run cooler but are still warm to the touch. If you want to spend the bucks for good LED's look no further than
LEDtrailerlights.com. You'll pay 3 times more but these are great quality LEDs. I have quite a few of these in my 5er and they put out excellent light. They also have voltage regulators and can be used from 10-30V. When looking for LEDs, always make sure they state "warm white" if you want the incandescent look. They have 252 lumen 921's there which are equal to your standard 921's. They used to have 300 lumen 921's which are noticeably brighter than the OEM 921's.
EDIT: They also have 1156/1141 bulbs.