[CentOS] OT: P4 Vs Xeon for Linux

I have just had delivered a new HP Proliant server and it is based on an
Intel Xeon 2.8GHz processor. On site already we have an Acer Altos G310 with
a P4 2.8GHz processor. 

The new HP server was destined for another site with about 30 persons to
service some simple file and print sharing and to manage their email
(postfix + MailScanner). The Acer is hosting our Intranet, file and print
sharing and soon to have our email + bacula backup services for potentially
250 users.

Performance wise, would it be worth the small effort to move the Intranet
etc. onto the Xeon-based server and ship the P4 to the other site or will
the potential performance gains not be significant? 

Any insight appreciated.

Thanks