Horseshoe SI is fine. The rooms in the hotel are old but most rooms have newer mattresses and flat screens. The hotel is connected to the casino by a half mile covered walkway. There are a couple of moving sidewalks and, if needed, a shuttle that can drive you most of the way.
The casino has four decks; deck one is non-smoking. The diamond lounge generally has hot food in the evening. Drinks are not free anywhere in the casino, however, the DL offers free drinks for a couple of hours on Tuesday and Thurs. evenings.
As for dining, there is a steakhouse, an Asian restaurant, a sports pub, and a Paula Deen's buffet. There is also a 24 hour cafe on the boat and a small cafe in the hotel. I don't think there are any promotions right now for free buffets.
Finally, be aware that the casino is in the middle of nowhere. The nearest town is 8 miles away.
Have fun!