I just went through this as a first-time homebuyer so I have a great answer for you.

Numbers aside, each "type" of lender will have its positives and negatives, period. And just giving you a heads up, there may be a stylistic, personality-based clash that creeps up as you close that may have to manage.

My realtor had a mortgage broker that they highly recommended, and I honestly took all his recommendations, he did great with everything, except I had this killer rate with my solid bank. They in turn directed me to a "big-box" lender that could easily retrieve my financials, and low and behold, my realtor strongly disapproved of them. He even said we were going to lose out on deals with their name on my offer.

Anyway, that didn't happen. But down the road, after our offer was accepted, when I had a lot of lending-related questions, and my "big box" lender was interacting with me, well, pretty impersonally, my realtor wasn't really there for me, and they were very quick to criticize my lender when problems arose. And looking back, it's because I think he was used to having a solid mortgage broker carry his clients through lending.

My issue with my "big box" lendor is that I didn't have the feeling that I had a true point there on my team. As I was transferred from department to department, everyone was excellent at their job but some things did fall through the cracks. I had to ask for a couple of extensions because of some stupid mistakes on their end.

At the end of the day it all worked out and I was happy with everyone on my team and because of the fuck-ups I gained a ton of experience.