Most users who have uploaded videos are probably aware that it isn't available right away, but may not really understand why as far as encoding goes. If that process is sped up by such a significant factor, they don't have to worry about it. The 150x number is at worst misleading if you take Amdahl's law into consideration, but upload speeds really aren't at the mercy of site owners. Improving any part of the pipeline is going to be a big win, especially for video.