Easiest way to copy users from one Sitecore instance to another.

Hi,

we have done an upgrade from SC7 to SC8 a month ago.

For different reasons we didn't go live at that time.

We are now ready to go live, but we need to transfer sitecore users that have been created in the meantime to the new instance.

I have found some option

- serialization (loss of password)

- scripting all aspnet tables (drop and create)

  (not sure if there are differences in table structure between SC7 and SC8)

Are there more or easier options to do this?

All help is appreciated.