Google offered all free IPv6 peering to all major transit carriers. Cogent turned them down and said, no, you need to pay Cogent for this. They were the only carrier to do this. So Cogent uses other transit carriers to reach Google. If you're on Cogent, you don't have a direct peering connection to Google. They probably did this to balance out their ratios with other carriers, but it's bad from a customer perspective.

You're better off using another tier 1 carrier than Cogent if you use a fair amount of Google.