I usually tell buyers, if they have a relationship with a particular bank, they should apply to them first for a mortgage loan. In difficult cases or where there is an unusual situation such as a short sale or self employment, perhaps a credit union or smaller community bank can help.
On the surface navigating the real estate market looks easy. I find for some, especially with special needs, they need to get extra advice.
On a recent transaction I recommended to the buyer (I represented the seller) a mortgage broker when the bigger bank he was dealing with could not give him timely answers and this was a qualified borrower.
It would appear that as competition for lending heats up there are smaller lenders and their agents willing to go the extra mile for the business.