Running as a 24/7 Plex server in my home. OS is Ubuntu Server (command line only). This machine is connected to my TV and home computers via wired ethernet and I also can use it through Wifi throughout my home. Connecting to Plex from other locations over the net works fine. I don't often use multiple streams but I've had it running 3 at the same time transcoding with no problems whatsoever. It should be capable of more. I also have it running Crashplan for automatic backups of it's data to the cloud.
Works great, the case is nearly silent and very compact, I like it much better than similar cases out there, having the motherboard above the power supply instead of underneath it allows for better cable management. I'm only using the stock CPU fan and the stock fan on the case, it seems to be maintaining enough pressure inside the case to keep dust out as it looks dust-free inside even after running for over 7 months in a basement. I will have to upgrade the hard drive fairly soon but I was planning on that anyway, I just wanted to get up and running for a reasonable cost. It does hold quite a bit of data though, I have close to 400 movies on it now and over 1500 TV episodes plus all of my music and pictures and still have about 300GB left.