Put simply its a an industrial embedded specification motherboard with a normal industrial board price tag. With this sort of board you tend to pay more but much longer guaranteed availability of the same specification of board unlike the short time frames of availability of most consumer grade boards.
You also tend to may more for passively cooled boards with no moving parts. As you are not likely to sell the required number of board to amiga OS users along to make a board thats just for Amiga clone OS thats why you see boards like the sam440 and EFIKA being used to run amiga OS's as they can make a few larger sales to other customers to help make production cost effective.
The down side is you wont get the fastest board in the world as for most of the sort of devices these boards are target at just dont need or want a supper fast and hot board.