Either is fine. I've personally never used one, I just stay mindful of where I work on my box, what shoes I'm wearing, etc etc and always touch the case (bare metal) while it's still plugged in to help 'ground' myself. Then I hang onto the box while I unplug it and move it right to my work surface.
I have yet to experience any static being discharged my components and I sometimes even forget to take the precautionary steps
Though, I do
live in a humid area, that's why I feel comfortable forgetting sometimes.
Personally, I feel the wrist-bands are a waste of money, just do what scottie does by touching a PSU that's plugged into the wall