I sent my application by special delivery on 24th September. Called Nationality helpline on 15th October to request my passport back. Advisor confirmed my application had not been allocated to a caseworker yet (almost 3 weeks), but they will send my passport back although the caseworker may request I resubmit it at a later stage. I called Nationality helpline again on 19th October because I had still not received my passport back. They confirmed my application was with a caseworker now, apparently since 16th October. I was put through to the caseworker, who confirmed my passport had been despatched via SMS (Secure Mail) that morning and I should receive it on Monday. Today 23rd October, I received a delivery from SMS and to my surprise a letter stating that my application had been SUCCESSFUL!!!
I am very astonished how quickly they have processed my application. Don't know if it helped that I asked my friend, a GP, to write a reference for me, perhaps.
Now I just have to wait for my invitation letter to the citizenship cermemony.
GOOD LUCK TO EVERYONE !