I'm not sure about Jack/Gwen (the dynamic is a bit too brother/sister for me to be comfortable with it) but some vigourous Gwen-defence went on over at torchwood_meta when we held our character discussion.

Therefore, since I'm supposed to be dissertationing, not Torchwooding, I shall helpfully supply this link (http://community.livejournal.com/torchwood_meta/1129.html)> :D