I see what you mean, but this is just a personal computer. I wouldn't be using this in any sort of production systems (nor am an IT guy).

What appealed to me about using Btrfs was that I could dynamically add more disks as I was inclined to upgrade, I could get data striping, snapshots, data deduplication (not implemented yet though), and since I was planning on running Linux, there was no practical solution for using ZFS. The fact that I couldn't pull the drive or that corruption might take things down doesn't concern me too much because if I wasn't using Btrfs I'd be using Ext4 and I wouldn't imagine it would be any better.

The documentation could probably use a little fleshing out, but in the little I've done (very little) setting things up, it was pretty straight-forward. As I said, I have two drives in my pool. When I installed Ubuntu, I only selected one for /home as Btrfs and then later added the second and rebalanced. Both adding and balancing were two simple commands (that I can't remember off the top of my head but were something like 'btrfs add' and 'btrfs balance')

I don't know about any automatic sharing, though, sorry. I'm sure it'd be pretty simple to set it up, but it might not be optimized for those cases.

Likewise, I just built a new computer and I put two 1TB drives in there and mounted them together as my /home using Btrfs. I haven't played around with it too much yet but so far it's been running buttery smooth. This is under Ubuntu 10.10 with a stock kernel so I'm not exactly at the cutting edge of kernel releases.
Something I haven't worked out yet but was hoping to figure out was getting file cloning working (copy-on-write) in places where I want distinct files (no linking), but don't want to waste storage if I don't wind up changing one.