LDN - Luminis Developer Network

Has anyone successfully completed a Luminis II -> Luminis III.2 migration? If so, I'm hoping to get a couple of answers on some things:

1) How large do the databases get in Luminis III.2+? Our test migration should give us a good idea but we're sizing storage at this point so if anyone has some guidelines that would be helpful.

2) Can a test migration be performed without affecting our Luminis II box? I'd like to just do a test migration and then put our Luminis II box back into production so we can play with our new III.2 environment for a bit before doing a production migration.

3) Any idea how long a migration takes, excluding email since we have an external mail server setup and we're not migrating that at this time?

Thanks,

Kent