Quote:
	
	
		| 
					Originally Posted by the.Mtn.Man  and Kobo, unlike the Kindle and Nook offerings, didn't reserve a large portion of internal storage for purchased books while leaving only a tiny sliver for sideloading. | 
	
 This is true for the Nook but definitely not for any Kindle at least since the Kindle 3 (don’t know about 1 and 2, never owned those).
You can fill the Kindle up to the brim with sideloaded content, and technically at least, cloud storage is unlimited if you’re into that.