We have a nice computer set-up and a nice TV setup. I bought a Chromecast back when they were only available in the States since I thought it might link the two together and I've been quite happy with it. To start with it was more of a gimmick than anything else, being able to cast YouTube to a big screen is great, just not something you do all the time. Anyway, Chromecast got some new channels and my brother has long used a media server application called Plex on his Mac and Apple TV box at his home in England to stream stuff from his computer to the TV. Best of all, once I installed Plex I could do the same with the Chromecast and we could even share libraries (I'm watching The Wire for the first time thanks to this sharing).
The only slight downside to the Chromecast is that it has no interface. It needs to be controlled through a smartphone or tablet. This is fine for when I am in command, but it rather precludes my wife from the fun because she isn't as techy as me. Anyway, for Christmas the US company I work for, NewTek, bought all its staff a Roku streaming stick and a year's Amazon Prime. This is a lovely pressie for staff in the States because it means they get free access to all Amazon's streaming video (and can pay to watch films that aren't on Amazon Prime). However, with the international boundaries, copyright law and so on, that is not available to any of the staff in the rest of the world and I thought there wasn't much point replacing the Chromecast with the Roku...
It turns out there is a point after all. The Roku comes with its own remote (which is RF so I can't put its controls onto our Harmony remote, which would be even better), and navigation is done on the telly. This means my Fona can access all the stuff on Plex, including my brother's recordings, through the TV with a simple, familiar user interface. Because we have a very high speed internet connection, it's worth going into the Plex settings on the Roku to change the default picture quality up to 8MB/s 1080p and changing the sound to 5.1. Obviously that isn't magically going to give programmes higher picture and sound quality out of nowhere, but it does mean you'll get the best out of what you have.
Interestingly, this morning I found out about RARflix, which is a different user interface for Plex that gives more info and better filtering options. More on that as I use it.
In short, it looks like the Roku is going to replace the Chromecast and it may even be that I spring for a Roku 3 so that I can use our Harmony remote rather than having to have a second controller.