I have no problems getting files from my Note 3 to my Surface 2 via USB connection. It should work with the S5 or any Galaxy devices. It might be the cable used, or try turning on the USB 3.0 function connection on the S5.
The Surface 2 is just great tablet. It was not designed like a full blown Windows like the Surface Pro lineup. "It's the iPad to the Macbook". A Suface 2 is way more functional than an iPad. This is what I carry around for reading PDF books, writing my paper with its great type cover and for my presentations connected to a projector. I can even miracast it to a smart tv directly. The kickstand and USB 3.0 are most useful.