Just make sure you’re comfortable with the interest rate if going either route.  

We have many efficincies under management with a ~10% vacancy rate with prices ranging from 485-625 depending on location property quality and amenities.

It's no different than their 2-year, low interest rate teaser houses.

What interest rate are you getting?

Tenant covenants and agrees to pay interest at the maximum lawful rate or eighteen percent (18%) interest, whichever is less, compounded annually, on all unpaid Rent, damages, and other amounts owed by Tenant, excluding late fees, from that date of Landlord’s final accounting until such time Tenant pays all such outstanding amounts.

But higher tax rate in PG county. 

Wow and I thought I was old school!!

Since companies have a limited lifespan (10–18 years on average), cities must attract new businesses to maintain job opportunities.Factors Companies Consider:Low Operating Costs: States with lower property taxes and insurance costs.Low Crime Rates: High-crime cities deter businesses and tenants alike.Natural Disaster Risks: Avoid areas prone to disasters, as recovery can take years, impacting your rental income.City Size and InfrastructureFocus on cities with metro populations over 1 million.

For the $525K property, with the low mortgage rate(you will probably never get a such low rate), it might make sense to hold onto it for now, especially if you can still sell it as a primary residence within the next three years and avoid capital gains taxes.

I don't do this for a living and have no real world experience, but at 40% down, even with a 7% int rate, that seems like a high monthly payment.