Built a fully automated media center for my mum using OpenElec (SickBeard + Couchpotato + SABnzbd + Usenet + XBMC). Had the setup running for a few years on my Mac Mini at my house, but was awesome to see it achieved for a fraction of the price.
Oh and at work we are using it to control a robot but can't say much more for another couple of weeks :D @sidgtl
I used mine for a similar purpose: allowing my grandmother to watch certain Spanish TV shows over the Internet. The shows are actually freely accessible online, but she doesn't know nor wants to learn how to use computers (which I completely respect!), so I made a simple UI controlled by the TV remote that downloads & displays them.
Incidentally, I used an Arduino as an USB-to-Serial converter for a TV remote receptor I had built when I was 15. It's a waste for such a simple purpose, but it wasn't being used for anything at the moment.
I'm blown away that you can load up and run with this. Isn't SABnzbd pretty RAM intensive? Are you doing this with local storage or networked storage? Does this handle 1080p, or are you running mostly 480 media?
I'm full of questions on this subject mainly because I've been holding out on purchasing a Pi for this exact application until they come with a bit more power.
I ran all those services at once to try out the performance, and I have to say turning on SABnzbd took the biggest hit. SSH'in for example was just dam slow. I am not sure how you manage to run all those with XBMC on as well. I was using raspmc distro, not sure that makes a huge difference.
Use OpenElec it's a dedicated distro for this. If you try setup those things individually as you would on a desktop you are going to have a bad time. And yes SABnzb is slow as hell extracting but all her TV shows download and extract in the middle of the night.
Are you using just the one Pi for all of that? Not done any serious benchmarking but my tinkering left me with the impression it would be fairly unusable with all that running on the one machine.
Oh and at work we are using it to control a robot but can't say much more for another couple of weeks :D @sidgtl