I've been using Windows 7 x64 since the RC days. It's awesome - by far the best operating system that MS has ever released. Yes, I've experienced the BSOD, but they've been hardware issues. I have seen applications indirectly cause the PC to lock up, but I'm fairly certain that they're also hardware issues (whenever I approach 100% CPU utilization on that particular PC, the PC locks up and can't recover without hard reboot).
I actively discourage everyone from using any previous MS operating system, and definitely from using the 32-bit platform, at the moment.