only one way to know for sure - the proof is in the progeny.
What have you got to loose?
But, in response to your second post, no, that only applies to true F1 hybrids. These lines are multiple poly-hybrid crosses. Each plant is to some degree a one off, although they are all representative of a desired outcome, albeit, not "the same".
If you make an F2 - you will create MORE diversity, because an F2 makes ALL genetic information available in the line. You are talking perhaps billions of possible genetic re-combinations.
All the same, it's worth it - if you plan to actually explore a couple hundred seeds. You WILL find some amazing plants if you commit. Headbanger is an excellent line with many proven winners.
dank.Frank
I just started a few nevils x oaxaca, 24k and gmo x headbanger (male looks and smells like my 2 best og girls in veg). Im going to flower them young just to see if I like the male. Got a few hundred of each. Also made some f2s and crossed with chem 91 s1, one of her offspring and bruce banner.