I have a Roku 3 for almost a year and it works really well, nice design, nice controller.
An important note to Canadians though - an Apple TV is easier to set up to watch American Netflix.
Roku once you purchase and register it, you are forced into a Zone.
I set up Apple TV with youtube help and it took 10 mins to get American Netflix working flawlessly just by changing DNS and setting it to US.
Another thing is American Netflix as more B+ and AA titles than Canadian Netflix, which is mainly C and D rated films.
Hope this helps!!