I've been using kirkwoods, rpi and mk808 for a while now and I want to share my experience with these devices. Sadly I can't compare to A10.
Kirkwood is super cheap ARMv6, still the best platform for headless USB/gigabit linux (I'm using it as USB NAS, router, print server, http server). debian and arch installation works and is well documented.
The mk808 has USB, integrated wifi instead of ethernet, mali 400 graphics, hdmi and armv7 neon/vfp3 processing power. debian or ubuntu on that device is very capable especially compared to raspbian on rpi, which must be the slowest combination I ever used in the last 10 years.
It seems the "picuntu" brand stands mostly for very scattered or non-existing docs, mostly windows/novice/android-user style forum posts.
But there are some people in that community that make available good working kernels, one of them runs debian instead of picuntu's ubuntu.
All solutions still require flashing the kernel image from a windows PC.
the picuntu installer is a joke - a non-working bloated bash script, you'll probably want to edit it or do manually what it tries to do for you - I'm still searching for better docs.
The rpi is completely unresponsive, the usb hub that provides the 2 USB ports at the front is buggy, ethernet is connected via USB also and just 100Mbit/s.
If all you want is a very simple hdmi terminal without need for any processing power tinycorelinux on rpi might be an option, but don't even think about compiling stuff, it will take days.
In practice it's not cheaper than a mk808, which already comes with all needed accessories (cables, power adapter, smaller case), so I don't see any reason to buy this overpriced old ARMv6 hardware.
One good thing might be the accessible gpios, but I never tried them.
After my (8gigs) SD card got filled twice, first time because of swap and second time because of oversized source and build directories, it broke completely with fs corruption so I lost all my compiled libraries: boost, cheetah, wpa_supplicant, openssh,...
I dumped my rpi after that.
netbooting would have been useful...