The advantages I see are that it will save money with using white appliances, it has a clean look and photographs well for marketing, won't clash with nearly any wood-tone flooring. 

You could do a 1031 exchange at this point and roll the proceeds into another property.I think I would sell now when you wouldn't have to pay capital gains taxes.You could use some of these proceeds to buy another rental property and take advantage on a low down payment on your next owner occupied property.

For people in highest income tax there is no tax advantage to borrow.

@Branden Bennett It seems extremely likely that your dad has equity in these properties, and if he does, that is no small investment advantage.

Also, there are a lot of other advantages to single family homes.

We are also looking at refinancing to take advantage of lower rates which would add another $140/month in cash flow.

There's no real advantage to 0% vs 3% unless you see a big interest rate drop; otherwise keep your cash in your pocket. 

My biggest regret to date is not taking advantage of an FHA on a multi unit as my first property.

They each have advantages and disadvantages.

This area of the business (timeshare) has struggled to provide owners with a dignified exit, leaving so many openings to take advantage of owners from crooks and shysters.