Yes, all v2 styles should work without changes.
We have done deep changes in the core, but taking care to not break anything. Anyway you can find differences rendering old scenes because:
- UVW Mapping is completely redone. RC2 used an approach which was not working well in many cases, so we had to rewrite it.
- Random values are not equal. So, for a RC2 style you will get randomness, but different values.
Besides that, if you find something is not working as it should, please tell us.