The answer is...it depends. I lend in all 50 states but am only comfortable in 6-8 of them. It's an advantage to an investor buying in multiple states. An originator, working in a new state, should disclose that upfront. Most Realtors are helpful when I do that and appreciate the disclosure.
I prefer to work within my own state, Washington. This is simply because I'm familiar with the area and the real estate practices. For example, some states practice closings or title insurance differently. I also have relationships with appraisers and when you get too far away from home, you lose that. I prefer to recommend clients to other mortgage professionals within the state they are financing property.