I had a consulting job where I lived away from home for about 1 year. The apartment the company put me up in had all utilities but did not have cable, so I went with Sling. Sling markets itself as "live" TV, implying the service you get with Sling is the same as other TV providers. I can assure you it is not. "basically" what Sling does is give you access to the various channel apps. Let's say you like to watch the History Channel. If you turn on the history channel in the evening with your TV provider, you might watch 4 or 5 different shows over a certain time period. Sling doesn't do that. You pretty much get one show for the entire evening. As an example, on Mondays you might get 20 episodes of Pawn Stars on Sling in a row. On Tuesday it would be a different show for 20 episodes, and so on throughout the week. You cannot select what show you want to watch on Sling like you can through other apps, so if you want to watch Pawn Stars on Tuesday, you are out of luck. Not every show on History Channel is shown on SLing. So if you want to watch war documentaries on Sling, there is a good chance it won't be there.
Sling does work better for some of the other channels like TBS, or CNN. These are closer to what you get with a traditional provider.
For my application, AppleTV, Amazon Fire stick, or Roku, (you would need one of these devices to get sling) were much better solutions. However, these only work really well if you already have a TV subscription. If you have a TV subscription through a traditional provider, you can generally log in to most channels through your provider and have access to all the shows available on the app. If you cancel your regular TV, you have to pay for the apps. Hulu also works well if you are only after certain shows.
In summary, I didn't "hate" Sling. To be honest, I subscribe to the MLB package so I watch baseball every day for 7 months a year. Sling wasn't terrible or anything, just don't think that you are going to get the same experience you get with a traditional provider for $25 bucks a month or whatever it is. It wasn't bad in my application. I was living in a temp spot, and I had baseball to watch almost every night. Despite the outrageous pricing of traditional television options and the fact that we use 5 of the 150 channels, I still would not use Sling as my only source for TV.