Here's a great article from Forbes magazine:  Secrets of a mortgage loan officer

Goes over the difference between a loan officer at a bank or an independent loan officer...

" A loan officer at a bank or a credit union is typically just the smiling face of the institution—the officer’s job is to accept an application that the borrower has filled out, and then hand it off to the underwriting department."

"An independent loan originator, on the other hand, typically renders more service to the borrower, including things like advising the client about the best loans available for their purposes, gathering documentation throughout the process, ordering the appraisal and communicating directly with the underwriter to ensure that the loan gets approved."

"Mortgage rates available at an independent loan originator, whether it’s a broker or a small banker, won’t be higher than those offered through a big bank. In fact, in many cases, the rates are somewhat lower, partly because independent mortgage brokers typically have more loan sources available to them compared to the big banks, which usually just have a handful of loan products to offer prospective homeowners."