I wonder if there is some issue on your system causing performance problems with Chrome. For example, I know there is an incompatibility between Nod32 4.0 and Chrome 5 that causes insanely high ping. I was getting 10 ping in speedtests on Firefox 3.6.3 and 550 ping in Chrome 5. After upgrading to Nod32 4.2 the issue was fixed. Chrome went from sluggish to blazing.
I find Chrome to be as fast, or faster than Firefox in all circumstances. It is usually faster. The browser loads instantly on a Core i7 system with an Intel X-25M G2 SSD vs. 1.5 seconds cold start for Firefox (around 0.8 sec without Adblock Plus), but that's running off a fast SSD. It took significantly longer on cold start off a WD Caviar Black drive, which is similar to what most people are using.
Page rendering is amazingly fast. The Adblock extension isn't as good as Firefox, but it's ok.
I really do like Chrome's multi-threading and sandboxing. In Firefox, every time a download finished, the browser would freeze momentarily while NOD32 scanned the file (disabled checking in about::config, but still happened), and often loading Adobe Acrobat files would hang the browser momentarily. Because Chrome is multi-threaded, issues in one tab never affect another tab.
In addition, while Chrome uses more RAM than Firefox because of its design, you actually get the RAM back when you close a tab. With Firefox, RAM usage balloons unless you close the browser. I've seen Firefox use 1.5 GB of RAM after 2-3 days of usage. Close all the tabs in Chrome and you're back to 70 MB or so of usage. And Chrome also loads instantly, even with many tabs.
In conclusion, Chrome's performance isn't just marketing - it is the fastest browser available at the moment. If it's slow for you, something else is wrong.