Has anyone used Cloudflare's web analytics[1] product? Specifically, I'm referring to the analytics product which requires you to switch over to Cloudflare managing your DNS.

How accurate are these DNS level analytics?

I've added client-side javascript based analytics tools to my site (specifically: Heap, Google Analytics), and there's a huge difference in the data. Cloudflare says I've got over 1k hits, and heap says I'm at 10. I'm not sure what to believe! Could the difference be due to web crawlers, adblockers, or something else?

Thanks!

1: https://www.cloudflare.com/web-analytics/