FP before the appointment date

[JayaJaya]

To FP Gurus out there:

I read so many messages about FPing before the actual appointment date and even at a different center than the one on the notice.

Has any one who did early FP got their approval in a reasonable amount of time? Or is it risky to go early for FP?

What is the sequence of events after FP? (FBI, INS ...)

Thanks