I did the sling tv roku 3 deal a few months ago. It just takes some getting used to but I like the money I'm saving per month. I was spending $235/month on cable/internet. Thats down to around $105/month with sling TV/hbo/netflix/hulu/amazon prime and internet.
I added HBO a month after a had sling tv and they sent me another Roku 3 at no charge. Right now though I have a Roku 3 on main tv and roku stick in bedoroom.
Not sure if you know this (I didn't) but you can only stream sling tv on one device at a time.