We have 3 Roku's (the "hockey puck" kind with an attached hdmi cable) in our house in New Hampshire, and also a Roku smart tv. In our condo in Florida, we have a Roku smart tv and also a Roku ("hockey puck" size) that is attached to a Vizio hdtv. They all run pretty flawlessly. Rarely do I have issues, but for the minimal times that the tvs have crashed, I simply unplug the Roku and then plug it back in and the problem is solved. I mention that I have two homes with Rokus because I am able to compare different internet providers and have found that the Rokus work great in both locations.
They are fairly intuitive to set up. You just follow the basic instructions and you'll be up and running in no time. During the registration process, you will be asked for a credit card number. You will also have to set up a Roku account online. If you have any problems, there is a customer service number you can call I believe.
I have Netflix, HuluPlus, HBOGo, and Sling. Those are my monthly subscription channels. And my husband has a subscription to NHL. I think he is billed yearly for that. Netflix cost me $11.99 and HuluPlus is similar. Sling is $20.00. Sling has a lot of offerings that mimick cable tv. Netflix has movies, series, documentaries, stand-up comedy, and they have offerings for children. Netflix is a great value. A lot of things that are included with Netflix for free, Amazon Prime charges extra for. I have tried Amazon Prime, but I think my needs are better met with the subscriptions that I have. However, I do like many things about Amazon Prime. We rent and buy movies through Amazon, and you don't need Prime to do that. I don't hear many people mention HuluPlus, but my family likes that a lot as well. We have had Roku and these subscriptions for about 7years. We got rid of cable about 5 years ago. I should mention that Sling crashes a lot, so we will be getting rid of that.
We also have subscriptions that we don't pay for, like Pandora ( for music), and PBS (I watch Sewing with Nancy on there), and numerous cooking channels. My husband must have been a meteorologist in a former life, and he watches Weatherbug. We also get Crackle, which I would recommend you check out.
One thing I love about my Rokus is that the controllers have headphone jacks, so I can watch tv without disturbing anyone. Overall, I think Rokus are a great product. I have used other devices that were supposed to stream Netflix, Hulu, etc., and all of them crashed. (Wii, Samsung blu-ray, Sony blue-ray, Vizio tv with apps, etc) Roku rarely crashes. Of course, it is only as good as your internet service, but barring issues with that, I think you'll be pleased if you buy one.