One of, if not THE most annoying thing I've found with PlayLater is downloading videos (especially YouTube videos) and keeping all of the buffering time intact when playing the recording. This has added entire minutes to individual videos I've downloaded (I'm using a wired FIOS connection) and adds nothing to the experience beyond awkward pauses. I don't know if this idea is possible since downloading is based on your connection and if it can't keep up well.... Yet maybe PlayLater could be able to detect if there was a lot of buffering stops and tell you to try to redownload.
Removing buffering from PlayLater downloads