I used to watch lots of MKV and AVI vids, but in the last 5 years it's been mostly low quality Flash streaming and I don't hoard media any more. I prefer immediate viewing to waiting for a high def download.
On the other hand, I still hoard lots of Gb of mp3 files. No change there, but I can't use Spotify in my country.
We recommend quad core cpu if you want to see 1080p movies for Tonido server.