WowAce

During WotlK and Cataclysm, I used the bar replacement addon "Macaroon". I'm sure your aware of this addon, though if not briefly it's major difference from Bartender and other ActionID based toolbars was that each button could be it's own Macro.

Each button had three states which could be set by the user. ActionID, PetID, and Macro. Whilst in bar config mode, left clicking a bars button would cycle through the 3 states, right clicking a button would open a small configuration window for that buttons current state. So for example, the user could choose for a button to be a Macro, right click that button, a small window would open whereby the user could choose an Icon, and enter the Macro itself.

The addon also had a seperate ButtonStore screen whereby the user could drag and drop Macros from their toolbars to the ButtonStore screen, and vice versa. (note : I'm not sure how well that worked, it was a feature of the addon I never used).

The Macros where completely separate from Blizzards own Macro UI.

The advantage this offered was that because each button could be its own Macro, the addon offered (theoretically) unlimited toolbars, each containing an unlimited amount of Buttons. More crucially, for me at least, each character had an unlimited amount of Macros. I believe these Macros also could be longer than the standard UI allows (though again this was an issue I never ran into so I don't know how well that worked).

In every other respect, the addon worked similarly to Bartender.

Would Macrotext buttons be a feature you would ever consider implementing in Bartender?

try the addon macrotoolkit

having the ability to add a macro to each individual button is saving you like, 2 tiny steps. 1 to open the macro toolkit and 1 to drag it down to the action bar. Although what I think you're probably most interested in is the additional / unlimited macro feature compared to the small number allowed by the default interface.