Copying VMs between vCenter's

We want to copy all VMs from old ESX4 Hosts to new ESXi 5 Hosts. As I see it, we have several options:

1) Copy .vmx, .vmdk files and register on new hosts

2) use vCenter Converter (VM to VM) to transfer VMs to new Hosts

Anyone have experience of using vCenter Converter (standalone) and is it any good?

Thanks folks