I've updated a couple of sites now with the new files and on the whole it works fine, although I did have to change a couple of things which had been custom-coded and I'm going to make a list of things to be aware of which might help others so that they don't fall into the same traps I did!
One thing I wanted to ask about though - if the site uses other WebAssist features such as DataAssist pages, and particularly member areas controlled by SecurityAssist, presumably you can't just replace the files on the server such as helpergroupsrulesphp.php as this would erase any settings that were already in place - for example I have sites that have member login areas and a lot of custom Access Rules/Groups set up. How I would go about updating these sites?
I've also had one issue with one of the sites I've updated - the left hand links on the admin page don't work. I've included login details in the PM section - would you be able to take a look for me?