Hi @Grant Baker - I'll give you a contrary opinion so you have a balanced response!
If you work with multiple agents, expect them to get frustrated with you and eventually get little or minimal help from them. They'll know that you aren't dedicated to them, so they will similarly not be dedicated to you. This is how investors get a bad rep within the real estate agencies.
However, if you interview several agents and let them know you're looking to work with someone exclusively for your investment portfolio, you can vet each agent to find one that works well with you. Ask them about their experience, their own investments, their connections, how they've found deals for other investors... You'll find that some of the agents that you interview aren't up for the job. Hopefully you'll have a few to choose from, and then pick one. If you're still hesitant to work with one agent exclusively, just be aware that you're likely not getting their best.
If you interview them properly, you'll find someone that you can work with over many years. That person will know how you work, what you're looking for, how you like to do business, and can keep an eye out for things that you may not come across. They'll be an asset to your team and can even help you expand within the greater context of your portfolio, if you trust and build that relationship. If you go it alone, it's going to be a much harder process with a new agent each deal.
Whatever you decide, I wish you luck and success!