Wandboard Quad
I blogged last year about compiling Cyanogenmod for YW9300, but you might guess from the lack of updates that I never succeeded. The YW9300 had a lot of operating system problems, and I eventually lost interest in the device. The online shop w2comp.com even stopped selling the devices due to the problems, but it looks like they are back in stock now. The manufacturer might have fixed the problems, but I moved on to a different device for my personal Android hacking needs.
So, my current device is a quad-core Wandboard, which is a very nice little device with a Freescale iMX6 SoC. Freescale, Wandboard developers, and a company called Boundary Devices provide the source code of various different versions of iMX6 Android, which makes porting Cyanogenmod a doable task. Wandboard doesn't have Android 4.4 yet, but I'm sure it will be released at some point! Overall I'm very happy with the device, and I find the overall software and hardware quality to be superior to most cheap Android devices in the similar price range.
One annoying thing about Wandboard is the lack of NAND memory, which means I have to boot using an SD card, which is obviously much slower. The quad model has a SATA port, but using a SATA SSD with Wandboard would require routing of power and a much bigger case than my current one. Using the SD card makes the operating system quite slow, so I might have to connect an SSD anyway at some point to be able to do anything meaningful with the device.