In benchmarking tests done on the new Jaegermonkey version of the Firefox, the speed improvements are quite evident. It easily outperforms the newest Firefox 4 beta on both SunSpider and V8 benchmarks. But then again, Google Chrome is still the fastest on both these benchmarks. Therefore, the Jaegermonkey addition has done little in terms of how Firefox fares against Chrome.
But things are not that simple because, benchmark tests do not reflect how fast a browser will run when you use it in person, in the real scenario. This is why, it needs to be clarified here that the Jaegermonkey Firefox is a real improvement on whichever version you may have been using till now.
Moreover, despite Chrome achieving some staggering numbers in the benchmark test, you will barely notice much of a difference in speed between the Chrome and the new Firefox while using both in real life.
The Jaegermonkey team has put in a lot of work into beefing up the Firefox browser, including reverse engineering and endless debugging, which is a standard procedure before any browser upgrade can be previewed. Websites, which require enhanced Java support, should run faster on your system with the Jaegermonkey. The developers even claim that by the time it is ready for the final release even greater speeds will be achieved!