It seemed to me like mostly inconsequential stuff. It did not add back in Watney driving around the sand storm, or rolling the rover, or even typing (.)(.) when informed that the crew hadn't be told he was alive. It did add in a mention that Annie had two deadbeat ex-husbands, and showed Rich Parnell doing more of his calculations, etc. To me, the extra 10 minutes was mostly filler. If you bought the original release, don't feel that you also need the extended version. But if you haven't bought a copy yet, you might as well get it. One qualifier - I watched it while attempting to sand/shave/file an airfoil onto the fins of my Orbital Interceptor upscale. I might have missed something...