I bought the Roku Stick after less than satisfactory results with ChromeCast. I was concerned that my wi-fi wasn't fast enough (since ChromeCast had significant jitter problems streaming even SD content) but I have had no trouble with Roku in this regard. I am streaming Amazon Prime and Netflix content in HD with no jitter or playback problems. The only issue I have had is with the remote which seems to "lose sync" with the stick and I have to remove a battery momentarily to get it to work again. This might just be bad batteries, though they were new I installed them just a couple weeks ago, but I'm going to try fresh batteries to see if that solves the problem.
This is my 3rd Roku (in addition to a Roku 3 and Roku 2). I couldn't believe the results would be as good with a "stick". Was I ever surprised. Easy setup and very easy to use with the same quality and reliability of the Roku 3 it replaced, at half the cost.