Just went through a few of the ST2 sounds in ST4. They are not bad. I would say with the right fx they would do.
To be honest, I think these sounds have passed their prime. They are more trouble to install than they are worth. Let me put it this way, I won't be installing them anymore. If something happens and I have to reinstall ST3 and ST4, ST2 libraries will not be included. What sounds are in ST2 I have other replacements they would serve me better. And MUCH EASIER TO INSTALL!!
That said, if your still working with ST2 and a minimum PC, this is a good deal.