Cortana: What can it do and do I care?

According to net rumor, Cortana does some searching and accepts voice commands and gives voice responses and does snooping for Microsoft.   It used to suck up better than 100 Mbytes of RAM and a smidgen of CPU time.  Since putting in Creator's update big patch the other day it is down to 66.6 Mbytes of RAM and zip for CPU time. 
   After go rounds with Dragon Dictate and the average robocaller, I am not impressed with voice recognition.  I haven't gone thru a training session with Cortana.  I don't think I'm using it at all. I think I want to blow it away to save RAM and speed up things.
   So far, net searching only say you can use Regedit to add a key to the registry  (AllowCortana = 0) that inhibits Cortana from doing something while searching.  No directions for blowing Cortana clean off the hard  drive.   The only searching I ever do is with a web browser and Google, or on my harddrive with Windows Explorer.  
  Question:  Is it worth  adding the magic key to the registry?   Will it recover that 66.6 Mbytes of RAM, or does it leave Cortana sucking up RAM and doing nothing?