Re: They also do systems for humbler budgets
I opted for nas4free for my HP Microserver.
I recently upgraded from ancient FreeNAS 0.72 (original FreeNAS renamed to nas4free when iXsystems took over FreeNAS) and was pleasantly surprised that it happily imported the ancient softraid mirroed volume allowing me to copy it internally on the box to the newer larger ZFS pool.
Whilst similar, they each have their own emphasis on things. FreeNAS has introduced quite extensive plug-in system which may appeal to some.
The old 0.72 never missed a beat.