I downloaded 350 leads from Apollo, sent their LinkedIn URLs to Leadrocks, and compared the output.
From the 350 URLs, Leadrocks was able to find 100 leads with email addresses.
Like SalesQL this tool exports both personal and business emails. That is part of the mixed bag I am talking about. There is no option to limit exports to professional emails only (SalesQL can do that).
I sent the 340 email addresses Apollo found (out of 350 leads) and the 100 email addresses Leadrocks found to my go to email verifier Millionverifier. The company I was interested in does not let the verifier verify the email addresses, so the Apollo list was reduced to 0 after verification. The Leadrocks list was reduced to 38 valid email addresses, almost all of them personal email addresses. In my experience, a lot of Verizon and Yahoo email addresses bounce nevertheless, so after filtering these out, the list was reduced to 25 valid email addresses.
This test results was influenced heavily by the specific company, as it seems to block SMTP email address verification.
If you do not want personal email addresses, Leadrocks may not be your tool at the moment. But in this specific case it may actually be useful, because it is possible to reach employees of companies blocking SMTP email address verification.
Leadrocks offers me a free code for writing this review.