I've been looking at the new Rockchip RK3399 based devboards. Of note is the $99 Rock960[1]. The major draws for me are the DisplayPort support, so I can use it with my iPad 3/4 display controller board, M.2 PCIe 4-lane, eMMC, 802.11ac. Firefly makes a similar one as well. [2]
Founder of Vamrs, ROCK960 manufacturer here, iPad 3/4 display is eDP interface and you can drive with RK3399 directly, you don't need DP and controller board. ROCK960 doesn't export eDP due to the small size, ROCK960 EE version has eDP exported.
I wonder what wifi chipset it has. Supports 802.11ac which I need. I should investigate this board, see if it allows monitor mode (low level wifi packet access). The RasPiB+ supports 802.11ac but the Broadcom based wifi doesn't allow monitor mode.
The RK3399 based SBCs are very interesting. Not only are they not complete jokes in terms of performance but they also have PCIe which can be used for SATA.
1. https://www.96boards.org/product/rock960/
2. http://shop.t-firefly.com/goods.php?id=45