I have already used Formatter 4 to format my card through a direct SD slot but as once it still seemed to resort back to Generic Hierarchal I also tried formatting the card when it was in my S4 connected to the PC via USB cable.
I now read that on the link below "If you accidentally insert your SDXC card into a computer that does not support SDXC (using a direct SD slot or USB reader/writer), the following messages may appear:You need to format the disk into drive 'X' before you can use it. Do you want to format it?
It then says

lease choose no/cancel. Do not format otherwise card is no longer SDXC format!
Well unfortunately this is exactly one of the formatting options I did!

I then put my card back into my S4 and works fine. When I connect to my PC I'm no longer asked that it needs formatted and can open it fine although this worries me after reading this message telling me to leave well alone.
Please, please PLEASE can anyone tell me if I have ruined my brand new 64GB card so that it is no longer SDXC? And if so is there anyway to reverse this and what the actual benefits are of SDXC if I have to worry about not having?
https://www.sdcard.org/consumers/sdxc_capabilities/using_sdxc#cards-for-pcs
I would be devestated to think I ruined my new card just by experimenting with a few ways of formatting!
Any help is so much appreciatted.