A fresh install of Windows 7 feels snappier than a fresh install of Ubuntu 12.04.
File Explorer -- starts in miliseconds
Nautilus file explorer -- takes about 3 seconds to start and 1 second to display the files
Chrome starts faster on Windows 7
Eclipse starts faster on Windows 7
The only slow thing I have noticed on Windows 7 is extracting ZIP archives which is about 3 times slower than Ubuntu.
My computer 2x2GHz Intel CPU, 3GB RAM, Intel GM45 GPU