- Mac OS shows storage space the right way, because it shows capacity in KB/GB (which is base 10 by definition)
- Windows OS shows storage space the wrong way, because while using base 2, it still claims to show you space in KB,GB (but actually it's GiB)
To what is generally better: Well for the common user GB might make more sense, since every storage device is marketed with GB in mind.
https://en.wikipedia.org/wiki/Template:Quantities_of_bytes
And people who feel cheated because of less storage space seem to ignore the fact that this tablet is running a full Windows Operating system.
I guess it's just the mindset of many to think of tablets as "big smartphones" instead of compact full-fledged computers.