According to this test in PC World:
We also measured a noteworthy 7 percent speed increase in our Autodesk 3ds max 8.0 SP3 (DirectX) test on the HP Pavillion desktop, which had an nVidia GeForce 9300GE graphics board. nVidia's drivers appear to be better optimized for Windows 7 than Windows Vista.
My real world experience running Windows 7 RC on a low end and low priced notebook has been very positive compared to using Vista on the same hardware and with the same software (Office 2007 SP2, Visual Studio 2008, SQL Server 2008, AutoCAD 2010, AutoCAD Architecture 2010, etc). I actually can use most of these software at the concurrently up and running something that was not possible on Vista.
I love the boot speed, shutdown speed, general speed in day-to-day usage, lower memory consumption, stability as well as I do like some of the new look and features.
The notebook is an AMILO Pa 2510 with AMD Turion 64 X2 Mobile Technology TL-58 (1.9 GHz), 2GB RAM and an 120GB hard disk with 5400 revs, ATI Radeon X1200 video card and 1280x800 WXGA screen. Have to test a stationary later on. More on this notebok.
I’m pretty sure you get a better performance also on a high end stationary PC.
What is your experience?