[Mark N]

So I've been testing out this upgrade. I think it goes without saying but perhaps it should be noted that if you use third party modules, this upgrade will quite likely make many of them not function correctly - in my initial testing I found that the WebsiteCM Dynamic Tabs and the Altered Cart One Page Checkout did not function anymore. Not to single out these two modules - they just happen to be two that I use on my site that I noted problems with.

This is clearly a very significant upgrade, affecting over 300 files, probably more depending on how much your site is customized.