I tried switching from Pidgin to Empathy.  After importing my accounts,
I looked at the log for a contact to check how well the logs imported.
The logs showed conversations with messages sorted by sender, rather
than by time, making conversations completely unreadable.

In other words, a conversation like this:

me: line 1
someone-else: line 2
someone-else: line 3
me: line 4
someone-else: line 5

gets shown in Empathy's log like this:

me: line 1
me: line 4

someone-else: line 2
someone-else: line 3
someone-else: line 5

- Josh Triplett