For me, the upside of an LLC far outweighs the downside. 

If the income on both units outweighs the debt PMI or not it may be worth exploring!

Don't pierce the corporate Veil: This can occur if the entity either is poorly capitalized.Inadequate Initial funding of the entityor fails to maintain a separate identity from its owners ( using the business bank account for business purchases, maintaining separate books)Conversion of entities Assets for Personal BenefitAnother factor that poses a risk of piercing the corporate veil is the draining of entities assets (such as payments of large salaries to shareholder-employees) that leaves the entity with inadequate resources to pay its debts.As you earn more income from flipping business, you should definitely elect to S-corp to save on SE tax. but if you are not making around 80k Plus, the benefits are outweighed by the complexity and expenses of maintaining it

When I first started educating myself, my first thought was to partner for the same reason you explained...however I quickly learned that the benefits of going in solo into a house hack deal far outweigh the cons.

HUD prices are attractive but HUD doesn't negotiate, doesn't do repairs... do you think the pros of buying HUD outweigh the cons?

I have a lot of new areas I am focusing on at the same time in our businesses and as much as I would like to hire a full time Business Developement Manager or other employes, the payroll would just outweigh the benefits unless everything went exactly as planned.   

It's a worthwhile hour just to check it out as they are very competitively priced and their capabilities may outweigh their limitations. 

But the advantages far outweigh any possible disadvantages (of which there are very few, in my opinion).

So the question is, do the upsides out-weigh the downsides? 

My take - keep your properties under a LLC structure and pay a higher 30 year rate, and take advantage of growing faster, as the cash flow will outweigh the higher interest rate in the long run.