I've been doing this regularly for years, and it's always taken a few days - so I wouldn't describe it as "very fast", but I've never seen it take more than a week.
I submitted a Facebook request on Nov. 18 and had the file on Nov. 19. I submitted a WhatsApp request 8 days ago and still haven't received anything. Interestingly, their service promises it within two (or maybe three?) business days.