I did consider boards from the usual MSI/ASUS/etc. but they were either too expensive or not available. Distributor clearance had some ECS boards for good prices but they got sold out in minutes. can't blame the sellers, X79 boards aren't made anymore(except for these chinese boards) but the demand is still there so the price goes up. the chinese boards that aren't the earliest revision will support ECC Registered RAM which you can find cheap. taobao may have cheaper deals than ebay if you can read chinese/badly translated english.
The 2670 v2 will likely perform better in multithreaded apps at stock but won't perform as well for gaming.
https://linustechtips.com/main/topic/62476-post-your-cinebench-r15r1152003-scores-over-1000-submissions/ i got 1200cb for cinebench, the 6/7700k is slower but catches up when overclocked.
bios doesn't have any overclocking features(no XMP) and is quite basic. they sell under lots of brands so YMMV
added the 2 top fans last week so can't really tell yet. last case with the same fan config was pretty dusty near the intakes when i upgraded if that helps.
Windows 10 Pro N, yeah works just fine with windows 10.
got it used, looked like a decent cooler so i gave it a shot.