No advantage to 32-bit anymore. In the old days there weren't as many
packages for 64-bit and flash was a problem for some people. That has not
been the case for about five years. I have run 64-bit since it came out.
The advantage is mostly in the way the chip works. It is faster. It
addresses more RAM, etc. You might encounter the odd application that is
32-bit only, but now Ubuntu can install 32-bit applications in a
64-bit installation. The only problem that I could foresee is if you have a
special circumstance such as a graphics card which is not supported by the
kernel and you have to go outside the repositories to find one. It may only
come in 32-bit, but that is a long shot.