the lower the scope the more in line with the bullet.
i have one on 2 556 uppers, 9mm ,2 22 uppers and one like it on a 308 AR-10 and soon a 762x39 upper. that will make 7. they all but the 308 are used on my full auto, no problem so far, several 1000 rds each.
if you will only have one or two, go for the gold, but i have other rifles too so i cant pay $400 times 10 for optics.
the only bad thing about them is you HAVE to turn them off or the battery will die in a day or so. you get used to turning them off and having some extra batteries.