Basically, wholesale lenders use mortgage brokers as their loan officers. They offer a lower rate to the broker, the broker adds on his compensation, and the rate is usually about the same as you would get using a mortgage banker. Sometimes the rate is lower, sometimes higher, depending on how much compensation the broker adds on.

Mortgage brokers also learn the "hot points" of various wholesale lenders and can handpick the lender for a borrower which may be unique in some way. He will be able to submit your loan to either a portfolio lender or a mortgage banker. Another advantage is that, if a loan gets declined for some reason, they can simply repackage the loan and submit it to another wholesale lender.

One extra advantage is that mortgage brokers tend to attract a high number of the most qualified loan officers. This is not universal, because mortgage brokers also serve as the training ground for those just entering the business. If you have a new loan officer and there is something unique about you or the property you are buying, there could be a problem on the horizon that an experienced loan officer would have anticipated.

A disadvantage is that mortgage brokers sometimes attract the greediest loan officers, too. They may charge you more on your loan which would then nullify the ability of the mortgage broker being able to "shop" for the lowest rate.