I actually still run an ENTERPRISE class OS (CentOS 5) on an HP Omnibook 6000 (800MHz PIII, 512MB, recently doubled from 256), installed for learning purposes, and don't see what's wrong with that. And 'this century' is already almost 11 years old
To the OP:
Welcome to the CentOS fora.
1) What do you mean by 'the mini versions'?
2) Can you update a 'mini version' after installation (assuming a 'mini version' is a minimal install)?
3) Can you install additional packages to a 'mini version' (again assuming a 'mini version' is a minimal install)?
4) The 'freezes' may just be timeouts for some reason, not lockups. Can you switch to the alternate consoles (Alt-Ctrl-F[2-4]) to see what's going on?
5) Again assuming a 'mini version' is a minimal install, can you provide more info on your system through getinfo.sh (please refer to the recommended reading)?