I have the Doc Artisan Sport Combo Wallet case for the 6 Plus and I'm very impressed with it. Haven't tried the Pad&Quill case, so can't comment there. The Doc Artisan case is just wonderfully made, with lovely thick grippy leather and the neat removable inner case that is held in place by magnets. Love it!
Here's my YouTube review, if you are interested: http://youtu.be/Hmh8R87mBnA