But that depends on what you’re trying to test. If you want to test your DSL/cable/fiber connection (and nothing else), it’s actually good if the ISP is hosting

But that depends on what you’re trying to test. If you want to test your DSL/cable/fiber connection (and nothing else), it’s actually good if the ISP is hosting the test server. If you want to measure the speed you’ll realistically experience in the wild, including your ISP’s peerings and whatnot, that’s another question.