You can go to the old page by visiting chrome://global/content/config.xul

However, this wont be around for long and will eventually be removed, so I'd suggest getting used to the new page

I suggest giving users the option to choose what they want... many users will find this bulky and resource intensive modification annoying. More GUI options gives users more choice.

We won't be maintaining two different versions of the same page. It's been re-written completely and the new version will be the only one.

Other than the obvious resource drain, the other problem with this page is that zoom settings are not saved, so if one uses a less bulky and common sense zoom setting, it is not honored.

This change is about switching components from XUL to HTML. You can see this in the new Password Manager (Lockwise) and has happened less noticeably for the main browser window (chrome://browser/content/browser.xul => chrome://browser/content/browser.xhtml).