Yes, I use it. It's really good.
It's in a stable release (version 5) and you are able to opt-in to beta releases of 'apps'. In real terms it's just a management interface on top of a Fedora install but I think it works really well and is just no hassle. I work on enterprise systems all day so it's a bit refreshing to just one click install some services.
My only gripe is that their release model really sucked, they kept releasing new versions which required newer versions of Fedora every few months and I couldn't be bothered with that. This meant some apps weren't available on some releases so it was pretty much pot luck.
I believe that will be changing with Amahi 6 - they look to be sticking with 1 or 2 operating systems (Fedora 14 or CentOS 6 [in the future]) which I will be happy with.
Pros:
- Easy Samba management with greyhole (samba shares across multiple disks)
- Easy DHCP & DNS management
- Easy install of 'apps'
- Full OS still available in the background
- Free dynamic DNS which I've never personally had an issue with
- Easy VPN to home using OpenVPN
Cons:
- Release models in the past have been a bit poor