SMH,
Congratulations and you are certainly not in the majority with them. The speed and success has alot to do with who the lender is and a bit of luck. Your file can land on the desk of an unresponsive nitwit at your lender or someone who knows what they are doing. I have gotten approvals in 7 days and 270 days depending upon the situation. It sounds like you did about average to get approval in 90 days. Hopefully they got you firm releases from deficiency (i.e it says in your approval letter that the balance is forgiven and they will not pursue the deficiency) otherwise you may get an unpleasant call in future.
At least it’s over and you acn move on with your life.