So I received my new winbook A730 which happens to have the AMD Turion 64 processor in it. The workplace decided to use me as a test subject for windows xp 64 and I've been into it for a week so I figured I'd blog the results.
Finding all the 64 bit drivers for my hardware was somewhat of a chore, but we were able to find everything except the drivers for the card reader which is a texas instruments model and the video card driver for the radeon isn't the same generation as the one in the laptop but it does work fine.
Performance wise I see very little difference from XP 32. Note that I haven't done any load testing but this is just my perception from normal day to day usage.
The big plus is that x64 runs IIS 6.0 which is great for my web development goo though I had to set up IIS to run in 32 and 64 bit mode which required some KB surfing and when it runs in dual mode the ASP NET tab in IIS goes away which is moderately annoying. The majority of software I use works just fine, Codesmith required some tweaks to the Xheo Licensing file and anything that uses the old Borland database engine simply does not work.
I also seem to have internet explorer 32 and 64 bit but for the life of me I can't perceive any difference.
Overall I'm satisified with how the laptop is running, however, and if you're interested in putting x64 on a primary development box it does work fine as long as you're willing to jump through the extra configuration hurdles for drivers and setup. If you don't want to deal with that stuff, have exceptionally new hardware, or really aren't intrigued by being on a 64 bit operating system at this time there really isn't any compelling reason to mess with x64.