You have a 4.375% interest rate on an investment property that cash flows really well. That cash can be used as reserves, can be put towards your next property, or put into another investment vehicle.
By refi into a 10 year note, you are greatly increasing your risk. Your monthly debt service is now significantly higher which means you really need to have all other 3 units rented out in order to break even I'm assuming (3 because you said you would move in). Also, what happens if something goes wrong? You will now have a huge monthly bill that you must pay.
I'm not going to tell you how to think, but looking at mortgage loans and comparing how much you pay in interest is not a beneficial exercise IMO. You're paying a lot of interest sure but you're using leverage to make a bunch of money. None of that interest REALLY comes out of your pocket so why are you worried?
Lastly, return on equity is a good metric for how much your money is making you. If you refi into a 10 year note, you will be adding A LOT of equity into your property, but only cash flowing like $100 per month. So as you get some serious equity, your return on equity is going to be diminishing rapidly. I don't know your purchase price, but given the monthly payment I'm assuming somewhere in the $500k range. By year 5, you'll have something like $200-$250k of equity and only making $100/month. Holy smokes that is bad.