I have been using 64-bit on all the machines I own that can run it. While the features are the same as the 32-bit versions, it’s the ability to fully utilize all the capabilities of your machine is what I love.
Now many people ask me should I run 64-bit Windows on my computer? There is really at this stage (who knows for the future?) only two things to consider when making this decision.
If you have 4GB of RAM in your machine, and lets face it many of the newer machines quite often do, apart from a lot of the lower end smaller machines, then you definitely want to go 64-bit as the architecture of that OS will fully utilize the memory you have.
On all my machines, where I can, I run 64-bit, and have had no problems from applications for business to games… love it.