Ponytail Elastics: Metal or no Metal?

I have had to keep my 8 sample SisterLocks bundled to shampoo and protect them from sweat. So I have been experimenting with ponytail holders. So which do you think is less prone to pulling or snagging your hair - metal or non-metal?

On a separate note, rubber bands were definitely not an option, but I did experiment with both of the ponytail holders pictured. One has metal and one does not. Believe or not, I found the metal elastic ponytail holders were more gentle on my hair. The "Ouchless" non-metal elastics seemed to snag my hair at the "rough hard" area on the elastic band. Do you see the raised area on the Goody "Ouchless" bands?

Honestly, the elastic bands with the metal did not pull my hair until the braided band itself started to lose its shape and expose some of the rubber that was used to make it. The exposed rubber snagged my hair, but at that point, I decided to trash it and get a new one.

So I choose the elastic ponytails with metal as my preference for healthy hair and ease of getting on and off.