For example, on AT&T fiber I get 11ms to Blizzard’s east coast servers, but on my other fiber connection it’s 77ms.

Ah, interesting. We switched transit providers a year ago and noticed a big improvement in routing efficiency. Small providers are usually at the mercy of their upstream peers unless they can build their own backbone links to an IX.

EDIT: I really don’t want this post to turn into a debate about the merits of doing this, I just want to discuss tools that are out there that could do this.

Too bad. ICMP echo requests to a local anycast server don’t tell you anything about the service or a provider’s ability to handle those connections.

As a small ISP, I would like to know what your goal is here, or at least what you hope to discover.