I have taken the plunge and started the migration to a new GoDaddy server (http://220.127.116.11/). New details:
CPU GenuineIntel, Intel(R) Xeon(R)CPU 5148 @ 2.33GHz
Operating system Linux 2.6.9-023stab044.4-smp
Plesk version 8.2.1_build82070918.10 os_FedoraCore 6
I was forever running out of memory on the old one and this will give me more speed and a supported Fedora operating system (Core 6). Also added Plesk 8.2.1, which will give me a bit more functionality over domain hosting, etc.
Transferred my parked domains yesterday.
Will move the active sites over the w/e probably, before closing the old one. Meanwhile all should be as was on the old server.
Now I just need to get to grips with Plesk...