I have been using this service for the last 15 months to track down and prove to my ISP that they are congested between 5-10pm every night (speeds tank from ~300mbps to ~20, often less). This has been VERY helpful in proving my case.
However, IF I happen to be doing something that is bandwidth sensitive, and the automatic test runs, it REALLY screws me over. It would be really nice if I could just "pause" the test for X minutes/hours or even just indefinitely, without having to cancel the test and restart it later.