Addintools is almost there, but still misses my most crucial UI feature, customization. For all of Office 2003's faults, it has robust customization. Create your own toolbars, populate toolbar buttons with any command / macro / style / font / control / whatever, and customize the graphics on the buttons as desired.
For example, on my widescreen monitor, I keep my Word toolbars at a short two rows high (very efficient on real estate), but I have more than 160 buttons, and there's still room for another couple dozen.
I have single-click access to every command, font, and style that I might use frequently, or even infrequently, along with macros galore. All of them are in plain sight all the time and showing all their status information all the time. Compare with The Ribbon, where, if I am using commands on the Insert tab, I can't tell whether the current paragraph is formatted to "Keep with next" or not.
And compare with Addintools. Can I paste unformatted text easily? It's not easier than clicking my macro-linked Paste Unformatted toolbar button, which is right after the Paste button but has a green gradient clipboard instead of a yellow one.
By the way, my Excel toolbars and other Office 2003 apps have customized toolbars, too.
When Addintools includes customization capabilities, or if Microsoft provides an interface that I can select to be either The Ribbon OR toolbars & menus, I'll make the change to 2010. But not to 2013 with its goofy licensing.