Difference between 32 bits arch and 64 ones

[Xavi León <Javier.Leon-Gutierrez@upc.edu>]

Hi all,
   We have a server with a AMD Athlon 64 Processor and i was looking
   for a Debian port to this processor. But the sarge version for
   this architecture is still in testing.

   My question is if there is a lot of difference between the sarge
   i386 version and the AMD64 one (faster, reliabilty, etc.) and
   which one is better to install in a scratch installation of a
   server. I'm thinking (too) arround installing a Ubuntu 5.04 which
   has a full supported AMD64 version for this server.
  
   What do you recommend???
   Thx!!!

Xavi