Two sisters wanted to buy a house together after going through some tough personal changes in their life. They approached a lender who provided a pre approval but once they put an offer on a property the lender took around 8 weeks to provided another conditional approval. I was introduced around this time and managed to obtain an unconditional approved in just over a week. In some situations, and often depending on the circumstances of the seller and the market, this kind of delay could have caused the offer to fall through completely.
Having someone (a broker) to drive the process and be on hand to, not only make sure the lender has accurate and adequate information and documents to conduct their assessment, but to make continual follow ups and escalations if necessary, could make the difference between you securing the property, or seeing it slip through your fingers, with nothing to show but an enquiry and application on your credit file.
We also have a handle on which lender is best for each situation, and can often advise if a particular lender might be slow to respond in certain situations, giving cause for a more suitable lender to be sought out.