I've been using a combination of boards that I bought used from 2016-end of 2017.  Currently, with prices as low as they are on hardware I'm consolidating all my random_board_01 4-6 GPU rigs into 8-12 GPU rigs using Asus b-250 mining expert boards (30 to 50 usd on ebay used, 60 usd on amazon new) and 8gpu vedah frames (25 usd new on amazon) as I add new cards.  Just want to make configurations/maintenance a bit more uniform across the farm, to save time and a bit of electricity. 

Out of all the boards I've ever used for mining, this one has been the easiest to configure & maintain.  Rock solid and highly expandable.  Only real downside I've seen from it is lack of an m.2 slot, but I've never seen a real need for that on a gpu rig. 

I've thought about trying some riserless boards so I could ditch the headache of troubleshooting/finding bad risers...but just haven't done so.