For anyone else looking at these, here is another option. Same processor (J1900), same 4 port Intel NIC (82583V), slightly different layout and case. I've seen good reviews from people running that model w/ pfSense on amazon and redit. I ordered one of these last week but haven't received it yet. J1900, 4 port Intel NIC, 8 GB RAM, 64 GB SSD for $225 delivered (I bought the RAM and SSD on Amazon).
I can report that this version works fine. Installed 2.3.1, detected everything correctly, runs nicely. The CPU's are hot, 50 C (which is way below intel's spec of 107c but it's warmer than I would like). Enabled High-D w/ adaptive mode but that doesn't change the temp at all (though power usage should be lower). There is a thread here
about possible ways to get the freq even lower which may also help. I haven't put a power meter on it yet to see what the electricity usage is. I may put a 120mm case fan to blow air across it to help reduce the temp.