I like it iff I can hover over the human readable version to get the actual timestamp.
> People would more likely want to copy the actual date than the human readable delta.
I agree that this is true when copying, but text is primarily for reading, not copying.
Anyway, in the context of a comment/activity thread, how long ago from today that an entry was tends to be less important than the age of the comment relative to the other comments.
How is this "better at a glance"?!
Don't get me wrong, I share the annoyance with interfaces where I have no way to find the actual timestamp. It's better to only have a timestamp than to only have the "human readable" version with no way to get the timestamp. But (in my opinion) the best is to have the human readable version, with a way to get at the timestamp.