I just ordered one off of eBay, so if anyone is interested I can provide some impressions compared to the SHIELD. I've messed with the Cheap Chinese Boxes Running Tablet Android (TM) and definitely not impressive at all, but I'd like to see if this would be a better fit for the unwashed masses out there (who frankly don't need the power of the SHIELD like us enthusiasts do).
There are very good Android TV ROM developers over on the Fresktab forums that make it real easy to flash improved Firmware for these types of devices using a OTA update.zip and a USB stick.
Nougat Firmware support is actually pretty good from the manufacturer Videostrong as well:
http://freaktab.com/forum/tv-player-support/amlogic-based-tv-players/s912/mecool/firmware-roms/676338-rom-mecool-m8s-pro-l-tvstock-nexus-rom-android-tv-7-1