I am in the process of purchasing a home (conv. 30yr) and have met with one lender thus far. I notice that it is frequently recommended to shop around to get the best rate possible.  I realize that may make the most sense financially, but here are a few thoughts that are directly impacting my decisions going forward. 

1) the individual I recently met with is someone that I have known professionally for about 4 years now. I know him well enough to know that he is a pretty straight forward person and isn't afraid to lay out all the details and options available. I've even known him to tell someone that there are better options with other companies. 

2) the last time my wife and I went through this process we had to wait 5-6 days for our pre-approval. Not only that, but the guy who did it refused to send us a pre-approval letter until we found a specific property and were ready to make a bid (I'm not sure if this is industry standard or not, as I am new to REI). On one property the delay in waiting for a letter from him may have been why we didn't get it. The other lender (guy I've known for years) met with us and we were in and out of his office in less than an hour with a hard copy pre-approval letter.

3)  I think it is important to build a circle of people who we know well,  who work efficiently, and who we trust. 

So, experienced investors, would you recommend that I still visit other lenders or brokers in attempt to find better rates? or should I prioritize continuing to build off the relationship that we have already been nurturing for the last few years? I do understand that I may be possibly leaving some money on the table, but will that amount be trivial in comparison to having a long term business partner?