Sorry to derail this a little with a question,
I Never saw much use in the sandman perk, is it really worth the points?
I mean the ninja one is great, 2.5x damage makes a big difference, and happens whenever you pop someone from stealth if you are doing it right.
But sandman only counts if the target is sleeping, which is maybe like 1 in 10 or so. And when they are sleeping, they are pretty easy to get close to and put a bullet or two in the head (or more really) before they get to their feet anyhow.
Am I missing something with that perk?
And as others have said, the gauss is silencable, but even if it wasnt, the stupid level of damage it does would make up for the loss of some extra damage. Especially if you have time to charge it up, it should one shot about anything. its about 2.5x the damage of the closest other silencable weapon, damage wise.