I really don't see how it can save you time if you have to summarize the same source for yourself every time in order to learn whether the AI did a good job in this particular case.
There is a difference between creating a summary and double-checking if a summary is correct. It's kind of like coding something, or doing a code review. It does save me time, but that might have to do with how I think and what I enjoy doing. Everyone is different.
