So crazy that I have been parting out an almost identical build with an E3-1230v2 and a Supermicro board, Fractal design case, etc... and then boom the creator of PHP mentions that he built one too.

That's the sign I needed. Gonna take the plunge. @rasmus have you been on the 9.2 RC's and now the release or are you on 9.1? I've been having significant issues with 9.2. It's the best software out there to roll your own NAS though. Nas4Free is pretty rad too but falls significantly short when you compare it side-by-side with FreeNAS.

Also, regarding LAGG/LACP, I noticed some pretty radical throughput increases after experimenting it on my home network. It took me a while to decide on a Layer 2 managed switch, but I ultimately went with the TP-Link SG3216 (new from Amazon, pretty cheap for a 16port gigabit managed device) and it's been great.

I think that once a connection is open, it will route through one single interface, so it won't help much between two boxes. But, as you said, having multiple devices connecting and backing up simultaneously will take advantage of the multiple links.