How are Greyhound buses, good, safe?

I'm going to be taking an overnight trip from NYC to Niagara Falls on a Greyhound bus this labor day weekend. It's a 10hr 45 min drive when we leave and 9 hours when we return. However, I've heard some crazy stories how unsafe some greyhound buses are. I've heard that luggage gets stolen, bathrooms are unsanitary etc. I'm just wondering if any of you guys can clear up these things. Thanks.