Many of my customers will invariably want to use a random bank who posted a lower than average interest rate in the newspaper. I caution them, and actually insist, that they work with my tried and true list of lenders (or mortgage brokers who have a stable of lenders with whom they have a relationship and upon whom they rely).
That lender, who quoted the low rate, will NOT deliver, 99 times out of 100. The worst experience I had was with US Bank. The lender was located out of state. They required things such as the license of the home inspector. They questioned the borrower taking a better paying job doing the same thing he always did, in the same field. Never mind that the loan was to be only 30% of the value. The number of hoops my buyer had to jump through was absurd, and they never picked up the phone, and they ultimately never made any progress to approve the loan. Luckily, the buyer had double applied, and the back up lender was easily able to fund the loan.
Many times the problem is with an inexperienced, uninformed loan representative, who is eager to make a loan, and promises too much.