i for one have never been able to stand Gillian Clark. she tend to over-dramatize and over-sensationalize trivial issues.
she also used to be very anti-China. even though she seems to try to be neutral, you can tell her commentating has been a bit hostile to the Chinese, be it that she always tend to support the non-China side, or trying to down play the Chinese.
in recent years, however, she has slowly accepted the fact that it was futile and has since gone with the flow a bit more.
to really see what a good commentator is, we should look towards more professional commentators in the US and in other sports. little that i watch other sports like NBA/NFL, whenever i do, i always find their commentating much more professional than anybody have done in badminton.
another excellent commentator is cycling commentator Phil Liggett, who can make a sport as monotonous as pedalling from point A to point B interesting.