They're optional feats. Only thing people need to know is that if you allow them into your game, be ready for the damage spike.
Sharpshooter isn't as good as it is because of the -5/+10 damage mechanic. If that were all it gave, the feat would be fine. Sharpshooter is great because it negates all penalties for range and cover making it so a person can shoot from any distance he can see through anything less than full cover without any penalty. This severely limits a DM's ability to use tactics such as quality cover to provide enemies with bonuses. This is why Sharpshooter is such a ridiculously good feat. It gives so much and all of it is immensely useful and easy to use.
Sharpshooter isn't as good as it is because of the -5/+10 damage mechanic. If that were all it gave, the feat would be fine. Sharpshooter is great because it negates all penalties for range and cover making it so a person can shoot from any distance he can see through anything less than full cover without any penalty. This severely limits a DM's ability to use tactics such as quality cover to provide enemies with bonuses. This is why Sharpshooter is such a ridiculously good feat. It gives so much and all of it is immensely useful and easy to use.