It's not as effective as it used to be and I don't really recommend it to a beginner anymore. I actually found that multiple Support Specialists or a single Demo are better at handling Fleshpounds now than a Sharpshooter is. Sharps have to aim at a tiny little area on the FPs head, and if they miss they're screwed (hell even if they hit they're kind of screwed since it instant rages the FP, good luck hitting three more on HoE after that), plus they can't handle groups of enemies at all. The Xbow has kind of been neutered, sadly.
Double or even triple Support can just open with a triple Hunting Shotgun blast to the face, then finish FPs off with the AA12 easily, clearing out everything behind him because of the shotgun penetration. Same with Scrakes. And a Demo can just destroy FPs or Scrakes with a Pipe, while a Support can just clean up whatever is left, no hassle. I don't really see the need for a Sharp anymore on a 6 man team, especially on Hell on Earth where it takes 4 headshots for the FPs. On larger maps maybe 1 to 2 Sharps would be worth it, but on every other smaller map (which is like, 90% of what KFs maps are) I'd rather have 2 or 3 Supports, and MAYBE one Sharp. I feel bad for Sharp getting nerfed so badly, but at least it means we won't be seeing M14 spamming dumbasses anymore.
As for the Patriarch, Sharp is crap against him now. Not nearly as good as he used to be. I'd recommend Demo over him, or Support once again. Six level 6 Supports with AA12 + Hunting Shotty in a room with only two doors will just rape the Patty so fast it's insane, even on Six man HoE. Once he comes in, weld him in and go to town and he will drop in under 30 seconds. Level 6 Sharp with Xbow can't even hope to take him down as fast or efficiently.