Considerations re: converting 2 condos into a 2 family home

[Nhu Vu]

Hi there, 

When my wife and I purchased our first home, we bought a condo. It is the first floor unit of 2 family home that was bought by a developer remodeled both units and converted the multi-family into 2 condos. A few years later, our upstairs neighbors decided to put their unit on the market. We decided to buy the unit so that we could control who lived upstairs and to add it to our investment portfolio. 

We've since purchased a single family home and are renting out both condos. We will likely hold onto both units for a very long time.

My question is: would it make sense for us to convert the condos into a multi-family?

From what I can tell here are the pros and cons: 

Pros:

• * less taxes to pay on the multi-family vs. two condos
• * no need do the additional taxes associated with an HOA
• * Since I own both condos in a 2 unit HOA. One of the mortgages is a non-conforming mortgage that has a higher rate (a 7 year ARM). Converting to a multi-family would allow me to lump the mortgages together and refinance

Cons: 

• * the overall value of my assets is less
• * if we decide to sell, I'd have to spend the money to convert back into 2 condos

Are there any pros/cons that we're missing?