The glossy screens on tablets are quite reflective so limit their use outside if you want to use it to read or play games. You really need to be in a shady area. The Kindle 8gb model only leaves about 5gb for your apps and storage. I can't comment on Amazon Prime as I am more of a reader and their 'borrow a book' offer is limited to one book a month. As I don't buy many items from them the postage benefits didn't warrant the £49 per year.
OnePlus 5 review