FreeNAS looks worth watching but given that they describe is as Alpha/Beta software would you really want to commit your data to it.
Don't know what to say to that other than I've done four of these. All of them have been running for 9-12 months and none of them have experienced any data losses or other reliability issues. Can't say the same about my experiences with Windows Home Server.
I also think the alpha/beta designation sounds a lot scarier than it actually is. I suspect the FreeNAS people are doing a little CYA here. FreeNAS is built out of established well-tested software components (FreeBSD Unix, Samba, PHP5, Lighttpd, NFS, etc.) so it's not quite the same as the beta of a product built from scratch. It's also open source, so should something go wrong, there's an active community of support available to get things fixed.
Also it uses its own filing system so you have to have FreeNAS running to be able to get to the data - realistically what are the chances of troubleshooting problems if anything goes wrong?
Very good actually!
FreeNAS uses the Unix File System (UFS) which is not specific to FreeNAS. UFS is one of several file systems used in the Unix world. It may be a stranger to the Windows and Linux crowd, but it has been around for years. There's a nice intro article about it here: http://en.wikipedia....iki/Unix_File_System
You can also mount and read UFS formatted drives under Linux. A quick Google will point you to several how-tos if you ever need to do that. One example: http://ubuntuforums....wthread.php?t=683493
You can also do it under Windows with ufs2tools available from SourceForge. See: http://ufs2tools.sourceforge.net/One big caveat:
Most problems with FreeNAS come down to ignoring, misreading, or misunderstanding the documentation. RTFM is not an option if you have critical data. So unless you're willing to put the time into reading and following the manual you're probably better off going with a turnkey product like Drobo.