We're just comparing to the dashboard numbers. I have not done a recent comparison. When this was first launched (maybe a year ago?, older firmware) we were seeing Meraki numbers 10 times higher than the traditional people counter.
We have seen improvement over time and our store we used for comparison was extremely busy (lots of people dwelling and moving around each other and other obstructions). This is a very difficult use case for the MV camera.
We still love the people count analytics as a comparative measure. In 3 clicks i can get to the busiest minute, in the busiest hour, on the busiest day of the month and immediately see what the store looks like at max capacity. We find that extremely valuable.
If dead accurate people counts are important to you then there are more traditional options that may be better suited.