I did my biometrics at the London office but my application is being processed in Sydney.
I believe London is only slow due to the backlog of applications, they only reopened a few weeks back.
Ordering GCMS notes in my opinion is they best way of finding out your application status. You should be able to do this if you know your application details.
The details you will find on immitracker are just what members upload themselves. It is useful just to be able to see how other people's applications are progressing. Also if you sign up to the site it's quite easy to order GCMS notes through it.