I purchased a second Roku for the back room tv because we loved the first one so much.Easy to use and a great variety of channels to watch.I highly recommend it.
Overall I'm happy with the Roku stick. It solves a number of issues including reducing the number of cables.
Some apps are unstable (freezing, constantly buffering, loosing audio). I have high bandwidth (> 30Mb) and low latency connections and additional testing tells me it's not network related at all. Often the only way to recover is to reboot the roku.
The problem is either the Roku platform or the apps but likely a combination of both since different apps have different problems. NBC and CBS are especially bad. Netflix is the best, Hulu is not too bad, HBO is OK.