A few things about Sling TV. It does matter which device you use it on. I've had mores success with it on the Apple TV (4th Gen) as opposed to the Xbox One version.
I've had both Playstation Vue and Sling. If I had to choose one, I'd pick PlayStation Vue. It's simply a better value as opposed to Sling TV. The only benefit with Sling TV is that it's on more devices. (Which isn't currently a benefit since the app runs poorly on most devices) The only reason I'm using sling for right now is because Playstation won't push an app to the Apple TV. (I could theoretically Chromecast PS Vue once I upgrade my TV) (And yes I know I could just buy the Chromecast or Chromecast Ultra)
TL;DR - Go with PlayStation Vue, if you can. I've had wonderful results with both but it may just solely depend on the device you're using and where you are geographically.
