Ranked in these QuestionsQuestion Ranking
Pro Supports shareable test URLs
jsPerf is focused on being able to share your tests, so it can auto-generate a shareable link for your test.
Pro Developer is open and active within the community
This is always nice, and the dev says he's "open to suggestions" as far as new features go.
Pro You can use Chrome/Chromium's built in benchmarkers with it
By setting the --enable-benchmarking flag, you can improve the accuracy of jsPerfs benchmarking through these browsers by using the built-in benchmarking extensions.
Pro Based on Benchmark.js, so you have the same timers
jsPerf is based on Benchmark.js, so you'll get the same benefits of Benchmark's high resolution and dynamic timers with a different codebase.
Con Can take some fiddling to get to work with ie9 and below
If you happen to be testing with one of Microsoft's older browsers, then you'll need to play around with the Java plugins a bit to get it to run.