If it is because you want to sell real estate, it's vital.If you want to be an investor, then my suggestion is take the classes, but don't take the test. 

Lots of classes/teaching to get the gist of things.

Us S8 investors know that investing in lower class areas, come with higher risk.

I used to do junk removal and demolition for these kinds of companies and saw all the worst case scenarios in columbus from tenants that can pay $800 per month. check the vetting requirements, raise the price to get into your unit. 900 per month is cheap in columbus if you are buying c class make sure to take a little more like 2 months rent so the people moving in aren't scraping by

While I will grant you that some areas will appreciate faster than others... the vast majority of our properties are C class blue collar rentals.  

There's not too many high cash flow areas anywhere in Florida, but if you looked for more C class stuff you should get better cap rates or rent to price ratios, so could check out pockets of areas like Casselberry, Longwood, Leesburg, Deland, Deltona, Sanford, etc.

I have to think the OP is talking about different asset class's than that.

Chicago has also seen strong appreciation in both home prices and rents the past few years.Worst part - Don't get lured into the D class neighborhoods because the cash flow looks good on paper.

We love it for our C class properties. 

Couple of different ways to do that:)Many parts of the USA don't have cashflowing Class A rentals currently.So, recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.So, when investing in areas they don’t really know, investors should research the different property Class submarkets.