These "investments" were pure speculation driven by a set of economic conditions which no longer exist.

thank you.Hi Jessica, I will say that if you're investing in California, you won't be finding any positive cash flow and it will be purely an appreciation play for the most part. 

But if your family instead was going to use it often, then you pivot from looking at it as a pure investment to looking at the value of your family’s togetherness and happiness.

And on top of everything, I think the last thing about my returns,  it’s absolutely 100% possible because it’s exactly what I’m doing and I’m not trying to sell one piece of property so like the old saying says when you assume you make an *** out of you and me so stop making assumptions if you don’t know have a clue about my intentions which really are exactly as I stated in pure nature and when I get out of it is a group of people I helped and in the future, I hope that comes in handy, and I’d like to prove you wrong so if you wanna direct message me, I’ll give you my email show you everything and show you how much of an idiot you are

I would echo what many other people are saying - decide what your reasons are for purchasing, is it purely based on returns or is it somewhere you'd like to also vacation?

The more common one I'm seeing is just pure speculation that the value will continue skyward in the future.

Was having a fun, purely academic conversation with someone and somehow the topic went from the stock market, ETF's, to real estate, to BRRR's and either he or I or both us came up with this and wondered is this a legit strategy that others have used?

That looks like your problem - only 3% down (can you get that conventionally if its a pure rental property - i'm not 100% but I don't think so) - with that leverage (97% LTV), pretty much nothing is going to pencil.

In other words, how would I calculate the return (from a purely financial standpoint) of "investing" in a primary residence vs renting and putting the money elsewhere (perhaps even into an investment property, but also considering buying a business)? 

They're designed for owner occupants but could be something in which you occupied for a duration of time and then converted to a pure investment later.