@Joseph Turner the biggest pitfall is DTI.

This ^^^The single biggest loss as we age is muscle mass and bone density (they are related)

Biggest downside is rate will be higher at 80% vs 75%. 

As for our personal experience in staying in RV park there are quite a few reasons why RVers will choose certain parks above others, but the biggest ones for us were easy to navigate and informational websites, advertising, good pricing and great reviews. 

The biggest issue is that although it offers accounting, it has no bank account import at all.

What's the downside?

What was your biggest mistake when choosing a market?

When analyzing properties and doing calculations, this strategy does not provide a good return for the first few years, but it most definitely does give me faster equity accumulation and gives me the quickest/biggest cash flow per year that trumps other situations with properties on 30 year fixed mortgages. 

@Rory Sweeney biggest challenge with most PMC software accounting is that they are cash based.We've figured out how to do everything we need in Propertyware, which is similar to Buildium.Just takes persistance!

Given the market conditions the two biggest reasons I see sub2 deals happening is if the seller has no equity in the home and is behind on payments.