This is the latest 64GB revision of the Teclast X98 Air 3G, the C5J6. They all seem to be using Samsung eMMC drives now, but this is surely dependent on the batch and stocks Teclast have on hand. I’ve seen the 32GB version with BWIN, Toshiba and Hynix brand eMMCs. The price has really come down, $206 from Gearbest now. I think I paid well over $250 for the 32GB model dual boot when it was released. If you can, I always recommend getting 64GB on a dual boot if you can as normally the 32GB versions only have around 6GB free in Android and 10GB in Windows, which is never enough.
The Windows image now comes in English! Finally, after the factory reset. I had English and Chinese only options. The set up was all in English and it will first boot after my the reset in Chinese, just reboot and it will all be in English (US). Early models I had to download and install English as it was only in Chinese. Teclast have seen all the international sales and wised up.