Well, since your sarge has a pistol, he can use the power weapon with +1 attack, that's something. And you could give him a bolt pistol if you really wanted.
My latest list of SoB has an IG infantry platoon with three squads bunched together, their sarges all have power weapons, so does the single commissar. And I used a WH priest with eviscerator. That's 16 attacks on the charge with reroll to hit, all powerweapons from the squad alone. ( and 3 more from the priest with an eviscerator )
As always with IG, safety in numbers.
And yes, hellguns aka hot-shot lasguns are AP 3. Stormtroopers are 16 points per model now too. But they've been given extra kickassness.
The main armoury entry has been removed and upgrades for various models are now listed with their squads themselves, along with the other squad upgrades.
Overall, a good thing I think. Makes outfitting squads way more easy than before. Though yes, some options have been removed because of this.
Infantry commissare can no longer have powerfists for instance.