I love it. The forum over there is great and always helpful. The product is advancing very nicely and when version 5 comes out there should be a lot of things that can be done that are not currently easily doable. I run a "special" distro of unRAID that was created by one of the forum members called bubbaQ that has some extra apps and stuff built in. I run all of my torrents on the server now using rtorrent on the backend and with wtorrent (web interface) on the front end. This allows me (with some prot forwarding) to get to the web interface from where ever i am. I can start torrents on the server from my work if i want, or from my parents house.
I am running the Pro version and currently have 5TB of space in the server. That is 2x1.5TB, 1x1TB, 2x750GB, 2x500GB, 1x160GB. One of the 1.5TB drives is the parity drive (this allows me to recover from one drive failure) and the 160GB drive is my cache drive. The cache drive is only in the pro version and is sort of a temporary storage drive when you are writing to the server. It allows for faster writes initially and then in the middle of the night a script is kicked off that moves the data to the correct place. It works pretty well for me and I have been learning a lot in the process.
Read up on there forums and on the wiki and you should get a pretty good feel for things. I really can't say enough about unRAID and how much i like it.
I will point you to
this thread so you have an idea on what kinda computer i ended up building. Those pieces and part are not exactly what i used but check out
my post about the main piece of my rig over at the lime-tech forums. Also look through the whole thread to get an idea of what everyone else has put together.
OK, I will stop there for now. Feel free to ask any questions that come to mind.
Check out the system and links i provided above. If you don't mind having another computer plugged in then you can place all of those drives into the server (drives can be any size in an unRAID server, the largest just has to be the parity) and still have the data protected.