Buy more or pay off?

[Michael Chewning]

Hello

New to hear so perhaps this is one thats been answered a lot.

We will be closing on our 3rd rental property in a few weeks. 

- 1 SFH that was our original primary that the mortgage is underwater on so we kept and rented, Still underwater 4 years later but same Tenants

- 1 SFH which I own free and clear through an Self Directed IRA (these funds are locked up since it a retirement account, cannot combine them with personal funds, lots of fun legal rules), owned 1.5 years, same tenant. Was meant to be a flip but was just taking to long to sell and began running into financing issues. Seems to be going pretty good now though after some rough mistakes.

- New Rental SFH - Being purchased with 20% down conventional investor loan

We also have our primary home which is a conventional loan.  We have pretty stellar credit so the mortgage companies/broker are happy to deal with us. My wife and I are both in our early thirties so plenty of time to retirement. We would like to keep our rental portfolio growing but we debate quite a bit back and forth if we are better off focusing on paying down the 3 loans or finding another property when we have the down payment. 

Any help, guidance, suggestions, recommended readings or tips would be appreciated. 

Thanks,

Mike