Phew! Got my passport today!
Wonder if it helped that I rang and spoke to someone at the passport office because my passport is dated the same day I made the enquiry.
Here's my finished timeline
Eligibility criteria: 5 Year Ancestry + 1 Year ILR
Language criteria met: Majority English Speaking Country
Method of application: NCS Brent (JCAP)
Date of application: 22-Feb-2016
Payment method: Debit Card
Date of receipt by UKBA: 23-Feb-2016
Date of acknowledgement (email): 01-Mar-2016
Date money gone off account: 01-Mar-2016
Date of acknowledgement (letter): 03-Mar-2016 (dated 29-Feb-2016)
Date of letter requesting biometrics: 03-Mar-2016 (dated 29-Feb-2016)
Biometrics done: 04-Mar-2016
Date of approval: 22-Apr-2016 (Delivered 27-Apr-2016)
Date of ceremony: 04-May-2016 (Camden, not private!
Date applied for passports: 22-Feb-2016
Date money gone off account: 07-Mar-2016
Date passports received: 20-May-2016 (Dated 18-May-2016)