I took a look at these Nextbook devices the other day. Performance of the 8" and the 10" are almost identical. The 10" has slighly faster SSD storage. The 8" screen is too small to be able to work with easily, particularly in the command prompt. The 10" is okay, works like a netbook and has a touchpad mouse on the keyboard, which is nice.
The price of the 10" is too high compared to the 8". I would have considered R2499 fair.
Below are the Windows 8 Experience Index Results (Rating out of 10).
Processor: 5.9 (Better than a dual-core Celeron Notebook)
Memory: 4.5 (Disappointing for DDR3)
Gaming Graphics: 3.7
Disk: 6.85 for 8" and 6.95 for 10"
Hope this helps anyone who may be interested in one of these.