I would put the interest rate on the debt vs the expected cash on cash return from buying cash flowing properties, I am not knowledgeable on bitcoin or promissory notes but if your making 200/month or 2400/yr for 10k that is a pretty decent return depending on the risks.

Suppose I am paid $10,000 for a job or service I perform and receive the amount in Bitcoin. 

The blockchain is probably the most secure means of ownership that exist you just have to do your due diligence as with everything else.

Combine that with a seemingly slow road to wealth and many would shy away from investing in RE in favor of bit coin or some stock or mutual fund for instance.

I come from the blockchain world, where a lot of conventions and shows happen at venues with casinos.

Should I use that money to pay off my MBA loan (23k) and invest the rest in crypto (Bitcoin, etherium, etc)?

Th interest paid on any portion used to buy more properties, boats, stocks, bitcoin, etc is not tax deductible.

It just wasn’t designed for real estate investors.InvestingAt some point in the future I may do a deep dive into each of these:WealthFronthttps://www.wealthfront.com/Fidelityhttps://www.fidelity.com/Charles Schwabhttps://www.schwab.com/Acornshttps://www.acorns.com/Robinhoodhttps://robinhood.com/us/en/Bettermenthttps://www.betterment.com/Qoinshttps://qoins.io/SoFihttps://www.sofi.com/invest/Marcus Investhttps://www.marcus.com/us/en/investInvesting / EuropeEasy MoneyAdmittedly I haven’t put much time into researching this one:https://easymoney.com/Non-Traditional InvestingSorry, I haven’t done any bitcoin research yet…meanwhile….eREITs are becoming more mainstream:Rocket Dollarhttps://www.rocketdollar.com/ One of the top names in non-traditional investing.

One last thing that I’d recommend looking into is Bitcoin.

To briefly touch on some important points, however …If you’re worried about a downturn, it’s not at all clear that precious metals and cryptocurrencies are uncorrelated assets or negatively correlated to the stock market, meaning in the event of a recession one should expect them to retain value (in fact, recent evidence suggests the potential for an opposite correlation of both Bitcoin and gold).If you’re worried about inflation, real estate is as good or better hedge than just about anything besides stocks.If you’re focused on returns, RE returns easily beat precious metals pretty much any way you slice it.