This thread prompted me to do a little browser hopping (I'd been using an unoptimized version of Camino up until this point). I've settled on Stainless - it's a great little browser and I'd urge people to give it a try!
Like Chrome, all tabs run in their own process - so if one tab crashes it won't bring the entire browser down. The UI is beautiful (in my eyes) - a unified URL/search bar, navigation buttons, and a bar of bookmark icons down the side - that's it! A neat (and rare) feature is that of parallel sessions - you can sign into multiple accounts of the same website by having a different session set up in each tab. Javascript is fairly quick too (quicker than Camino and Safari, but not as quick as Aurorafox) and it scores 100% on the Acid3 test. Overall it just feels very responsive - with hardly any lag when scrolling up and down and minimal load times.
Now for the bad: Other than being Webkit-based, little else about the browser is known because up until recently it was closed-source. Apparently the project has gone open source, but I have yet to find where it is hosted. There is also very little in the way of options/customizations - preferences are very limited, and there is no extension system either. But to be honest, if you install Glimmer Blocker then you get a system-wide adblocker anyway.
TL;DR: Stainless is FAST!