Forum Upgrading from 3.8.x to 4.2 - A question (or two)...
 

In a nutshell, this is what I have done so far:

Backed up 3.8.x database and files.
Created new database for vb4 implementation
Restored 3.8.x database and files to vb4 database and subfolder
Installed all modifications that we use in 3.8.x that are designed for 4.x
Installed and customized a style that is similar to our current 3.8.x style.

Now for my question(s):

Is there anything out there (not Impex, thanks) that will allow me to pull down an incremental thread/post/user/pm/etc. backup, convert it to vb4 schema, and upload it to the test site? I want to minimize downtime if at all possible. I would expect no more than 30 minutes of downtime which would be the result of simply changing one or two things to point the site to the live URL.

Are there any real differences between the user/post/thread/pm/avatar/etc tables from 3.8.x to 4.2?

Would it be best for me to pull the tables down from the vb4 implementation, and then merge the tables from 3.8 to 4.2 and then restore them?

Note: All database transactions are done by SSH. Web-based admin functions for the database are disabled for security reasons.

Thanks in advance and sorry if I'm asking in the wrong location.