Good discussion here, with alot of different takes.

I can think of 3 reasons that people have DRLs: 1.They were already on the truck, 2. they just want anything that is an option, and/or 3. for the safety intended.

While playing around with my light switch - I don't have DRLs -
I stumbled on the fact that if you LEAVE the headlight switch in the parking light position, it goes out when you open your door - no 30 sec. delay. This 'new DLR' [parking lamp] is higher on the front of the truck [increasing #3 above] goes on & off automatically, plus offers you the ability to turn them off, unlike factory DRLs.

This will also serve '03 owners well, in that it also accomplishes what Toyota did for '04s - fulltime instrument illumination, due to
readout issues. I like it - I haven't touched the switch in sometime, except of course, to activate the headlights. This also increases safety from the rear, as the taillamps are on.