If anyone has experience with these two products, I'd love to hear your opinions.
My personal opinion: while UAW has a steep learning curve, and all the articles have to be manually approved by editors (which can be frustrating to say the least), I have to say I've had great results, but only when combined with other methods.
I haven't personally used AMR, although I do outsource submissions to a freelancer and have had good results, even without using any other methods, and even for medium competition keywords.