I'm posting this from Chrome. I'm going to give it a try over the next several days and post my thoughts later in the week. I ran my own SunSpider benchmark and compared it to FF3.01. Overall, Chrome performed 1.63x (i.e., 63%) faster than FF3's already very fast performance on my very modest hardware (Athlon64 3200, 1GB RAM). FF 3.1 promises to increase their JavaScript performance with the introduction of what they are calling
TraceMonkey, so we'll have to see if Chrome can keep up with Mozilla's effort, but as with seemingly every Google product release, Chrome is still in beta.
For comparison's sake, Chrome was 20.2x (i.e., 2,020%) faster than IE7.