I've run a Mac server at home ever since the old AppleShare IP days. So naturally when Mac OS X Server came out in 1999 I transitioned over to it as well and I've been a happy Mac server user for years.
Why a dedicated file server?
I like the ability of being able to access my documents and important files from any computer in the house and while traveling. With a dedicated server my family's documents, photos, movies, music, etc. are easily sharable because they all reside in one place (backed up of course). This Mac stays on 24/7 and therefore is accessible from any Mac on my network. Mac OS X Server is a version of Mac OS X that offers additional services beyond what you get in a standard Mac OS X installation. You can run things like an FTP server, Mail Server, QuickTime Streaming server, iChat Server, Mac OS X Update Server, iCal server, etc. etc. All of these services are built-in to Mac OS X Server including the native ability to share files cross platform between Mac and Windows users. With Mac OS X Leopard and Snow Leopard, you can also add additional hard drives to become network Time Machine backup drives too. So for me Mac OS X Server is GREAT! It solves a lot of problems for me.
The NEW Mac mini Server
Typically my Server hardware is a Mac tower that I've upgraded from and the older one becomes the server. For example, when I went to a Mac Pro, my Power Mac G5 became the Server. My server doesn't have to be that fast of a machine, it just has to have FAST networking and lots of storage. Although my strategy had been just moving my old tower down after each upgrade, I really started looking at the Mac mini as an alternative to this. I like the mini because it's VERY SMALL and uses a lot less power (take that DTE!). Since it's running 24/7, using less electricity is always a good thing for my pocket.
So I was all set to buy an older Mac mini because rumor had it that NEW Mac minis were coming out. I figured I would just buy the previous version that was discontinued and save a few bucks. What I wasn't expecting was for Apple to introduce a Server version of the Mac mini!
The New Mac mini Server is brand new version of the Mac mini. It has two internal 500GB drives (no optical drive), Gigabit Ethernet, Firewire 800, intel core 2 duo 2.53GHz processor, 4GB of RAM, Airport, Bluetooth and the unlimited user version of Snow Leopard Server! You get the entire package for $999. Now I wasn't planning on spending $999, but the fact that this thing would have everything I could possibly want right out of the box and to get the other Mac mini configured the way I wanted probably would have run $600-$700, I figured why not? I hadn't planned on upgrading to Snow Leopard Server, but since it was included and already installed, I went for it.
My upgrade went extremely well! I was shocked at how easy it was to upgrade not only from Mac to Mac, but also from 10.5.x server to 10.6.x server. Like the Migration Assistant in Mac OS X, the Upgrade Assistant in Server transferred over all my settings. There wasn't really any data to transfer because all of my data is on an external drive (Drobo) anyway. The whole transfer took about 10 minutes.
What about the 2nd internal drive?
Like I said, my data is on the Drobo, so I don't really need 500GB of storage, let alone 2 500GB drives. So I shared the second drive as a Time Machine Backup Volume. It backs up the internal drive to maintain all my settings and I use it to backup any of my other Macs on the network too.
The Drobo is backed up nightly using SuperDuper! to another external 1.5TB Firewire 800 drive. Once a week I rotate between my backup drives and put one in the safe deposit box at the bank and pickup the other one. This way there is always a backup that is offsite.
The Bottom Line
The Mac mini server is a GREAT solution. As you can see from the photo above, it's smaller than the Drobo that it sits on. It's quiet, and pretty much ready to go out of the box. I'll also be interested to see if there is any difference on my electric bill, but even if it's a small difference (pennies), I will still feel better knowing that I'm using less juice to accomplish the same task. The Mac mini Server goes for $999 here.