>managing 80% of the info in double that time (20%) would surprise me. This isn't particularly difficult. If you skip the pleasantries at the start and end of

>managing 80% of the info in double that time (20%) would surprise me. This isn't particularly difficult. If you skip the pleasantries at the start and end of a talk and use a playback rate of 4x, you'll more or less get that 20% duration. 4x is quite understandable (once you're used to it) given how slowly people giving talks tend to talk. Though if a talk is really dense in terms of content, you might have to go slower just to give your brain a chance to digest the information. Most tech talks aren't that dense, however.