Ha, you made it to 6, that's impressive! I only got scheduled for one interview, the interviewer was a no-show, and they never answered any of my attempts to reschedule or even find out what happened.
The manager of the team I would have been going on (FF for Android funnily enough) knew of some of (and said he actively used) my past work which was probably a leg up.
In the end they were far from the worst interviewers (hello Hopper for that title*), but it soured me against Mozilla after putting that much time and effort into it and just getting a "we're no longer hiring for this position" form email.
*: Never paying out their tech screening "payment", to rejecting me over an answer I never gave (we didn't like when you said "XYZ").