[schade]

i've blead brakes using both methods .. for just doing a regular flush of the lines, the gravity feed method well work just fine, i've never had a problem with it.
It's even how we do it 90% of the time on our race cars.

If your replacing lines, then thats alittle different story as you'll have huge air pockets.

each person does it there own way, so do whatever works best for you and what you feel most comfortable with