i386 vs AMD64 for web/mysql server

[Eduardo]

Hello,

Today I am running my web and mysql server in FreeBSD i386 and I have
the chance of moving to AMD64 architecture.

This new server has 4 GB of RAM and 64 bit intel xeon cpus.

Should I move to AMD64 or stick to i386 ?

I don´t have a lot of experience with AMD64 and  would like to know to
know what you all think... also will the performance be better with in
the AMD64 ?

thanks in advance,
-Ed.