I'm upgrading to a new top-of-the-line MacBook Air (4GB RAM, 2.13GHz processor, 256GB SSD) and am debating whether to install the 32-bit or 64-bit version. Up to now, I've used Windows 7 32-bit since I had only 2GB on my outgoing Mac. I installed Windows in Boot Camp since there is one application where I need to use Windows XP Mode (which only works in Boot Camp). If I were just using Boot Camp, I'd go with 64-bit, but since I'm also planning to use Parallels, I'm a little less sure. I plan to allocate 2GB of RAM to Windows 7 in Parallels. Has anyone used this with the 64-bit Windows 7? If so, how well does it work? The main thing I'd be accessing through Parallels is Quicken. Everything else I use in Windows I'd likely use in Boot Camp.