Old thread, but some info that may help others, as I've been researching about DRL replacement with LEDs. In the past two months both of my OEM DRL bulbs have failed (about 22 month old vehicle). Very poor performance, considering that my previous DRL-vehicles have had OEM bulbs that lasted 9-10 years. So I'll be replacing the Halogens with LED.
V-LED, the vendor of the bulbs used by HemiPowerV8 to start this thread, now has a note on the bottom of their web page for these bulbs (at 5K WHITE PLATINUM 20 LED 7W BACK-UP/TURN SIGNAL LIGHT BULBS 3157 3156 4057 | 1 PAIR
Not for use in DRL applications, will void warranty."
and, as per Post#35 of this thread by the OP, the V-LEDs have not performed well in the DRL application.
So I'll likely go with the LEDs as per J13ntv's sticky thread about the Putco/XenonDepot LED conversions.
One question: Did the user test of the Neutron LED bulbs mentioned by Steve in Post#28 above ever occur?