If the Moto X 2 comes out this year, and Motorola puts its efforts in the right areas, it could be a great phone, even if it won't have the specs of the GS5.
I don't need a UHD display, or a metal body, or 4gb of RAM.
What I would like Moto to focus on is improving the Touchless Controls to make them more complete and useful. I'd like to see them drastically improve the camera's performance. And if they're so inclined, I wouldn't mind having a slightly more powerful SoC for the purposes of future-proofing. It doesn't have to be top-of-the-line, but it should be something better. They can even keep the screen at 720p to keep costs down.
I believe some of those changes will be made with the next Moto X model. So between the two phones, I'd have to go with the Moto X2 over the GS5.