I just upgraded my internal site to DotNetNuke 3.0.10. Rather than messing around with all of the files that may not be used, I backed up all of the old files in the site and then copied the new ones in. After resetting the permissions and updating the new web.config to hit my existing DB (I had also backed up the DB before this!), I hit the default.aspx.
I quite liked the upgrade script - it seemed to work very well and let me know what was going on. I hit my first small snag when the site finally loaded up. My old DB was still referencing portals/0/ as my main folder. Since I had deleted that but not deleted the DB, I just copied the old folder into the right spot. Everything seems to work well with the site. Of course, the custom modules that I had installed on the old site didn't work, but I didn't expect them to.
The next things was to load up the whole solution and try to compile it. Right off the bat, I got 73 compile errors. The first ones seemed to be related to a missing MakeNodeVisible method. After searching through the forums, I found all of these answers. After deleting my VSWebCache, I still had 71 build errors, so I set the references to DotNetNuke.WebControls an DotNetNuke.WebUtility to 'Copy Local = True'. That didn't do anything.
After actually looking at the error, I found the solution. The error (that was in turn creating 70 other errors) said that the FreeTextBoxControls namespace was not found. After checking that it was actually in the DotNetNuke bin folder, I added the reference and hit compile again. Everything worked just fine this time.
A little quirky, but now it's time to play!