Especially the ones where I had doubters saying it couldn't be done or my strategy was wrong.What's next? 

Currently, I'm analyzing different markets to see which one will best match my strategy.

I am currently selling a 16-unit apartment complex, the first one to sell since 1998 when this buyer bought this one!

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

One of the key inputs is a score reflecting a property’s condition (based on listing photos).

You would have to go after the one individual for non-payment and you could only remove the other three by going through the legal process like you would for someone on a verbal agreement, which puts you in a he-said, she-said situation. 

Are other flippers working in the area or will you be the only one.

I understand it will be hard to match (if not impossible) the 10% yearly income and 5% appreciation of properties (those are my numbers).

While short-term rentals in areas like Kissimmee, Florida, can pay for themselves and offer lifestyle benefits, the ROI typically doesn’t match what I see from my traditional portfolio of long-term rentals in North Texas.That said, short-term rentals can still be a great choice, especially if you're drawn to the area and the opportunity to combine personal use with investment income.

Neighborhoods Set the ToneSan Diego’s neighborhoods each have their own vibe, and we’ve learned that tailoring renovations to match is essential.