Mylar v. Flat white

I have accses to both, what do u guys think. If you want you can leave some reasoning.

I use mylar...but I dont think it's that big of a difference....mylar is supposed to reflect 97% and flat white 80% I think....but thats not going to effect your grow at all...

Flat white because its easy to work with...mylar when I think its going to boost my yields. I go back and forth because I'm a maniac who always believes he can outdo himself every grow.