Keep in mind that you're more apt to read negative comments than positive comments. It also depends on where you're reading them! That one site, we won't mention any names, but they are definitely full of critics who love nothing more than complaining about everything.
I have clients that absolutely refuse to sail unless they can get an aft cabin. They absolutely love them and just won't settle for any other type of cabin.
We've personally been in an aft cabin a couple of times and we've never had any problems whatsoever.
The problems you're referring to are problems I've heard from people in any type of balcony cabin.
As with anything else, it is what you make it. So don't listen to what others like or dislike and decide for yourself - it really is the only way to find out if it's something for you or not.
As I always say, what one person likes, another will hate and vice versa.