Hey John, properties that have been on the market for more than 30 days typically start receiving offers below the asking price, as buyers often perceive them as having room for negotiation.

If they tenant is $300 below market, that's costing you $3,600 a year.

@Susan Kang what is drawing you specifically to these two markets as compared to other great markets in the mid-west?

The Detroit market is cheap and on fire right now.

Now I spend my time making sure new investors entering the market do not make the same mistakes my wife and I made. 

.: I have a deal in a luxury market where I am looking to renovate a 5,000+ sqft house that is a bit outdated.

Regarding vacancy periods, you'll need to understand, Days On Market (DOM) - or find a great PMC that understands and can explain it to you.

Columbus is a great rental market and we have a ton of opportunities here.

The same goes for coastal markets. 

As far as which market, I'll leave that to realtors and investors in Florida.