Rolling is good.
What might be even better is a rolling distro with timely
updates to key components. Opinions naturally vary, but let's just say this entails kernel, DE (say, Gnome here, although some Gnome devs get very grumpy is you use the term "desktop" these days..), X.org and possibly some most central apps like browser and LibreOffice.
I realize anything's timely compared to Debian Stable, but as the Debian CUT proposal successfully argues, in terms of bug-fixing and reporting, using the most current versions of software is generally ideal. Versions that are still getting .point updates and close developer attention...
I'm probably preaching to the converted here, but wouldn't it be great if some developers from each of those key projects could be persuaded to use Mint Debian as their reference release build, fixing and testing platform? I'm only talking about building and maintaining their latest official releases here.
The MintUpdate manager could still be used for allowing slightly more conservative users to choose updating only when the "upstream releases" have been vetted and okayed for interoperability by the Mint Debian developers and feedback from cutting-edge users.
I realize that the above scenario presents a real "testing case" challenge, but I've always dreamt of not having to wait for many, many moons until I get to enjoy of the freshest, mintiest fruit.