I’m pretty sure the vBulletin upgrades will go smoothly as I haven’t installed many plugins and haven’t hacked any of the code at all. Plus the fact that Jelsoft have put plenty of work into the upgrade process.
ArticleLive on the other hand is going to be a handful :( I had to do some extensive hacking of the source code to make Web Design Point standards compliant (even with it’s templating system!). This means I’m going to have to upgrade my local copy first, make all the neccesary changes (which will probably take a week minimum!) and then upgrade online using the changes made locally. Ugh!