I just realized, and I mean it literally just a few minutes ago, that my processor Intel T5870 supports 64-bit. I have had this laptop (ThinkPad R61i) for two years mainly running Ubuntu 32-bit. So far I haven't had a problem with it until last week when my OS (12.04) crashed due to a bad software update (my guess).

Should I take advantage of my processor's capability and upgrade to 64-bit (and I know I would have to reformat my laptop completely for it) or just let it run with 32-bit without my laptop's performance suffering for using a higher end OS?

I have a 3.9GB memory, integrated graphics, and 130GB hard drive.