Snow Leopard 64 Bit Kernel - Switching between Apps

Snow Leopard felt slow on my MacBook Pro (5,5). Switching between apps felt sluggish. I usually run Safari, Eclipse an VMWare at the same time and often switch between these.

The MBP booted with 32 bit version of the OS X 10.6 Kernel (this is the default) - thx O.S. for the hint. To my surprise, switching to the 64 bit kernel made a big difference. Switching between apps is much (!) snappier. (I did not see any perfomance test discussing app switching!)

PS: You can boot into the 64 bit kernel by changing the file
/Library/Preferences/SystemConfiguration/com.apple.Boot.plist
to include the following Kernel Flags
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string>arch=x86_64</string>