I think Dish bought them out, it's not a perfect service, but has improved vastly in the year or so I've had it. I think Dish gave them the capital to put up the ad campaigns to get more subscribers to have the base to improve the service. I use it on my roku, and generally you can get a free trial. You can watch from a PC, too.
I will say that I had the roku stick that they used to offer free as a bundle with so many months of service. It's just not the best for something as taxing as what sling offers. We just went and got the roku premier plus from Costco. Processing power is better, plus we can hardwire into the router for better speeds. The app is much more responsive on the better hardware. Plus, I don't think the Roku Stick even does AC wireless.
They just released beta of a DVR service that seems to be working well. You get 100 hours of storage, plus lots of channels have on-demand selections.
I'm hoping that being paired with Dish won't fuck over the service in the end.