FYI- The problems with the 525-B units on FreeBSD 10 appear to be limited to the CF socket.
I ran a few quick tests here with a SATA disk and with an mSATA disk and it was fine one both. Though there are plenty of reasons to replace it ASAP (it's a space heater, among other problems), that may be a way to squeeze some more use out of it.
The underside of the access panel on the bottom has a mount for a 2.5" SATA disk, and at least mine has a cable inside already with SATA power+data on one connector. mSATA will work in the mini-PCIe socket that is directly across from the CF socket.
The socket for mSATA is circled in blue on the image above. The SATA cable is circled in orange. CF socket is in red.
I didn't run from it long term but I imagine it would also run fine from a USB thumb drive.