Given that—cosmetics aside—Windows 7 isn't really that different from Windows Vista, this was probably to be expected. Still, it was interesting to see the areas in which 7 really walloped Vista, and those in which there was little (if any) change. I'll turn the e-reins over to Michael Muchmore, who did the testing and wrote about his findings over on PCMag.com:
...The new OS starts up significantly faster than Vista on the same machine. And it's not just faster in boot time, but on a number of other benchmarks we ran, including video encoding, the SunSpider JavaScript benchmark, Geekbench, and PCMark Vantage. The only area in which the new OS didn't show at least a little improvement was in shutdown speed. We tested on clean installations of 64-bit Windows 7 and Vista on the same machine: a Dell Studio 14z running a 2.4-GHz Intel Core 2 Duo processor with 3GB of DDR3 RAM and Nvidia GeForce 9400M graphics...Be sure to read Michael's whole piece, in which he goes into greater detail about his tests and lists all of results—which pretty conclusively point to Windows 7 as the winner of this speed match-up.
In a new OS with a lot of new features, it's impressive that Microsoft has trimmed down and sped up the code.... Most of the tests showed about a 14 percent improvement—a pretty nice boost. Of course, your mileage will most definitely vary. I performed several of my tests on other laptops as well, including 32-bit systems, and got roughly similar results. Where there were differences, they were generally in Windows 7's favor. Overall, I'm confident that most users will experience noticeable performance improvement if they upgrade from Vista.
I definitely agree with Michael that not everyone can expect comparable results. On my self-built home PC, which has a Core i7-920 CPU and 6GB DDR3 RAM plugged into an Asus P6T motherboard, I haven't seen an enormous performance difference after switching between a relatively new installation of Vista and a completely fresh installation of Windows 7. The new OS gets to the login screen maybe two seconds faster than Vista did, and to a usable desktop another three seconds sooner, but Vista was never distractingly slow in these areas for me.
Sure, even that little bit of extra time is nice, but the rest of Windows and most of my programs run just as well under 7 as they did under Vista—certainly not worse, but also not appreciably better. The biggest speed gains I've experienced have been incidental ones: Installing Windows 7 in the first place took about half the time Vista did, for instance, and thanks to Jump Lists, the new taskbar has made me a lot more organized and productive.