Well, for me, WHS2011 has everything I need, and is rock solid (not a single OS crash in 8 years). It, along with Stablebit drivepool & Scanner, FlexRAID and a host of other things, like autobackup of clients, running an FTP site, SABnzbd, etc, is pretty much set and forget. Just keeps humming along day after day. The security risks touted for using older operating systems are not a deal breaker for me. I know for some they are. If something works great for me, and does exactly what I need and want, and does it well, I stick with it. YMMV! (my phone is 6 years old too, love it!) That's why I am sticking with SABnzbd too!
Thanks for all the great info. I guess I will wait to do further upgrades until I either run into an issue, or there is some new feature I must have.
And thanks for all the hard work keeping SABnzbd going. Best out there IMO.