(1) No I haven't, but I'm impressed with the new android tablets that you can buy now for £70+
(2) For pdfs, wouldn't you be better with an ebook reader such as a Kindle or Sony reader - similarly priced, much longer battery life, and much more readable in bright sunlight.
I have used a Sony Reader in the air and it works well, although its pdf handling can be a bit variable and I've not actually tried it with approach plates. I should.
G