In my barbarian playthrough I decided to take halsin with me to rid the place of goblins. It all went ok having halsin with you is offset by immediate agro from the goblins, but you know what he did when I defeated the last leader?
[/b]het turned tail and ran for the grove![b] and Tav even said goodbye to him, while being swarmed by a horde of goblins.
You can imagine me having a few choice words for Halsin....
Anyway, to me this was very much out of character for Halsin, I'd expected him to atleast stick around to the point where -that- fight ended. I guess that is my suggestion as well.