The review is very thin, not mentioning what the actual experience is like of having a dual-boot tablet. Windows use isn’t even really mentioned. Same-day update: As a Commenter pointed out, it’s because this wasn’t the dual-boot version at all!
And since there’s a buy link at the end to a store, this isn’t any kind of review I’d trust.
Onda V919 3G Air Dual Boot: 64GBs Internal Storage
Onda’s Dual-Boot Announcement
Onda Introduces Dual-Boot Tomorrow
Onda V919 3G Air Dual-Boot Coming
Onda Shows Dual-Boot Android-Windows 8.1 Tablet
Onda: Android-Windows 8.1 Dual System Coming