Here is an Android 4.4.2 KitKat rooted custom firmware for the Vido Yuandao (Window) M8 tablet. This firmware is based on the official firmware dated 2014/01/16.

(M8-4.4-20140116-ZZ.img / M8-4.4-20140116-ZZ-固件+刷机工具+刷机教程+驱动.rar) 

Build information:

Linux Kernel: Linux version 3.0.36+ (york@mid-Porsche) (gcc version 4.4.3 (GCC) ) #1003 SMP PREEMPT Thu Jan 9 08:58:15 CST 2014

Android build: vidom8/vidom8/vidom8:4.4.2/KOT49H/eng.hy.20140116.175637:eng/opinions-on-teclast-p90hdst-keys

ro.rksdk.version=RK30_ANDROID$(PLATFORM_VERSION)-SDK-v1.00.00

Custom firmware features:

• root with latest SuperSU version 1.91 (free version)
• removed most Chinese and unnecessary applications
• Google Play Store fixes so more application are visible/compatible
• updated busybox v1.21.0.git (2012-11-29)
• Unix like init.d boot scripts support, more details on init.d scripts here
• changed permissions on external sdcard to allow write access
• increased space for applications (/data partition) to 4 GB
• disabled OTA updates (may cause problems)
• added Google Experience Launcher (GEL) in addition to PiPO's stock launcher
• use optional package to fix broken apps (Contacts/People and Calendar sync)
• fix for multi-user support, implemented using didierm patch, thank you !
• kernel modules (cifs, tun, lan, serial, xpad) compiled by Oma & Crew RKTablets, thank guys!
• optional ClockworkMod (CWM) Recovery easy install package 

Download:  kasty-yuandao_vido-m8-442-20140116-rooted4_mu.zip

Flash the firmware with Rockchip Batch Tool 1.7,  use Restore button.

Please report any problem with this firmware, I can't verify this custom firmware works as I don't have a Vido Yuandao (Window) M8 tablet to test it.