I've had it pretty negatively affect my experience of using macOS due to hyperlinks taking seconds to open throughout the OS. Uninstalling it fixed the issue. I still haven't found a good alternative and am a bit sad about it.
Hey, Daniel here, the founder of Timing. I haven't had reports from other customers about Timing slowing down URL opening. In fact, as an engineer myself, I spent a _lot_ of time optimizing Timing's tracking to be as efficient and unobtrusive as possible.
If you'd like to give Timing another shot, would you mind reaching out via https://timingapp.com/contact with details on the OS version and Timing version you used, as well as the apps the problems occurred with? If you need a new trial to reproduce the issue, just let me know and I'll set you up with one.