I am not going to speak negatively about someone, but I would suggest that the maps and tools he uses with any tool investors use should be coupled with other tools to evaluate your investment. Relying on one tool alone can be a risky move and you might miss out on some great deals!
When I started PM in Cleveland I used his maps to see how he classified the grades. Although he's close to what I would use, his maps are a bit inaccurate in both grading classifications and geographic locations.
For example Rocky River zip code 44116 SFR sold in the last 30 days (15 homes) ranged from $235 -$1.075m the average of those $532K. He recognizes "A" class as SFR selling for $150k and up. You will not find a SFR in Rocky River for $150K on a regular basis. for that reason I cant trust the rest of the data is accurate.
The second claim he makes is that grading of Clark Fulton Area is a D/F. where SFR (last sold 30 days) are 58-127,500 Avg of $90k. I do believe the stockyards is a D/F but the rest of Clark Fulton can be seen as a C/C- and is quickly turning as gentrification (turning) happens.
I will say there are a lot worse Pm's and Agents out there! so be careful!