The last I heard, 32-bit Office 2010 was recommended by Microsoft as their preferred standard.
After a clean install of the aforementioned and then watching all manner of other installations , including Adobe CS5.5 and Lightroom 4, defaulting to 64-bit on my machine, I really must ask if Office 2010ís development now justifies installing the 64-bit version on capable machines. I have had the full 64-bit version on one setup from the outset and I encountered no trouble with it, but I have treated it as experimental.
I donít know if I was an idiot to install 32-bit or not, but itís not too late to switch. If there has been a change in Microsoftís position I havenít heard of it, but is 32-bit still Ďthe bestí?