As an owner of the Dell U2913WM, with the same size and resolution, I thought I'd relay my experiences from a productivity point of view.
Firstly, this is the resolution monitor you want if your setup is restricted to a single screen, or you have overhead space limitations. For me I tried a dual monitor setup before this, to get the extra screen real estate, but ultimately I had to give up on it as my desk space just didn't conveniently accommodate it. The reason I choose not to go with the more common 2560x1440 was two fold. One, my desk has a hutch above it that didn't allow for the added height, and second the price (though minor) was more for what I perceived to be a lower quality screen.
What the 2560 wide resolution monitors regardless of height allow for is a much more comfortable side by side windows 'snap' experience. I like to snap my windows left and right in Windows 7 to give that perfect 50/50 windows orientation when working. At 1920 wide (your typical FullHD screen) I still found many programs and websites to feel squished. I found after snapping the windows I'd often find myself adjusting the widths wider to accommodate what I was working on. With the extra pixels of the wider monitors I'm finding the 50/50 split to be perfect for just about everything.
Ultimately, in my opinion, it is the 2560 width that is important. If your desk can accommodate the taller monitor then go for it. But if it can't the 2560x1080 in my opinion is absolutely an option.
I can't speak for the AOC, but the Dell U2913WM is a phenomenal choice. Color representation is better then any monitor I've ever owned. I bought the Dell to replace an eight month old 1920x1080 Asus monitor that gets rave reviews online but that I always found to be atrocious. I knew I had problems with its color but failed to realize how bad the color really was on the Asus I replaced until I had it side by side with the Dell. But that wasn't my purpose of posting a comment so I'll leave it at that.
I think the article gives a deceptively negative review of the aspect ratio from a productivity standpoint by making the majority of its observations against the larger 2560x1440 aspect ratio rather than the more common 1920x1080.
I would agree though, that if your space allows and your pocket book doesn't cringe, the 2560x1440 would be the better choice. But if you fall into my category where the hutch above your desk doesn't allow for you to place the taller monitor under it the 2560x1080 resolution is the perfect choice.