However, on a more limited machine (Since when is a 4GB machine not good enough to browse the web???), Firefox definitely wins and is much more enjoyable.
I was a long time Chrome user ever since it came out. However, recent versions (on OS X and Windows) are unusable with a large number of tabs. Firefox handles many tabs much better.
Frankly the memory usage isn't as infuriating as the "tabs extend past the right edge of the window" bug, which has been open for forever -- I'd link to a bug report but it's a nightmare to find with a search engine because of how hard it is to describe. Firefox has a simple fix for this -- they let you scroll the "row" of tabs -- but for some reason Google refuses to fix it this way. It's probably too rare of a use case; you have to have a relatively small resolution monitor and at least ~70-80+ tabs open in a single window, IIRC.