What is the difference between the "Crawl Issues" report and the "Crawl Test" report?

[SBowen-Jive]

I've downloaded the CSV of the Crawl Diagnositcs report (which downloads as the "Crawl Issues" report) and the CSV from the Crawl Test Report, and pulled out the pages for a specific subdomain.

The Crawl Test report gave me about 150 pages, where the Crawl Issues report gave 500 pages. Why would there be that difference in results? I've checked for duplicate URLs and there are none within the Crawl Issues report.

[Silkstream]

I may be wrong, but I always assumed Crawl Diagnostics was part of the Moz Pro Analytics. Wheras Crawl Test was a public tool. (Like Open Site Explorer vs Links Analysis in Moz Analytics.) So using the tool from within Moz Pro was more extensive.

Disclaimer: This is just based on an assumption I've made in the past. Mozzers, correct me if I'm wrong please!