hi Abundy,
the performance of some applications is better on a 64bit system than on a 32bit system. Here is a article which compares the performance of a 32 bit Ubuntu 9.10 with a 64 bit one:
http://www.phoronix.com/scan.php?pag...u_32_pae&num=1
In the past 64bit systems had the disadvantage that some closed source applications like adobes flashplugin or teamspeak didnt work on it, but I think almost everything works on a 64bit system now.