I drive with mine on all the time, car turns them off auto when i turn car off so never have to worry about battery going flat etc, if i had a car that didnt turn off auto i think it would be another story!
If it's really bright outside, I don't, to conserve my battery and bulb life. If the visibility is in any way reduced, I turn them on.
It's really annoying when people don't turn their lights on during the twilight period. Some cars disappear in during dusk and dawn and doing a small thing like turning on your lights goes a long way to making your vehicle more visible.
Ive also heard the, but I wonder if that will still be true if everyone does it? I think the reason might be that people notice cars with lights on during the day because its 'different'......if everyone had them one then it might just be exactly the same
Sigh...
Dont drive with your headlights on during the day while travelling in an urban setting. There is a very good reason why DRL lights are 20-40% the brightness of normal headlights, and in addition they have a very very different beam pattern.