Except for the database I went for a complete install. I closed the old board, copied the database, and ran all the appropriate altertables. This way, I could still go back to the perl version if I needed to. I also copied all uploaded files and made sure all config options were the same. But other than that, it was like a new install, so it was quite painless.
I'll start adding the hacks I want, most of the ones I used before are now integrated in the main distribution so I want have to bother about them.
Also, I made sure the look of the new version was as close as possible to the old one to minimize complaints. Still got heavily flamed for forgetting to turn off censoring, and because I decided to try out the user grading.
There are still some things that should be fixed, like the fact that the button on the old polls looks weird and the old color tags used in the signatures aren't working. I've written a script for fixing all this stuff, but haven't had the time to test it yet.
There are a few who has had problems loggin in as well, but that might have to do with the fact that I changed cookie domain as well. And some of them because the referer check is on and their firewalls are removing the REFERER.
