12.04 is the LTS (Long-term support). There don't seem to be vast differences between the two (they are both based on Gtk 3, which is what I thing you're referring to with Gnome 3), but I think there have been updates to Gtk that have not been backported.
facelessuser wrote:If you are interested, I can give you the steps to get your system ready and build it on 12.04? Once the dependencies are in place, building the the Color Scheme Editor is pretty easy.
Thanks for the offer, but as I'm not a programmer, I'd rather not install a whole bunch of dependencies just for this. I'm also quite handy with creating themes (thanks in large part to ScopeHunter & PlistJsonConverter
My main use for this would be go get a quick overview of a new tmTheme, which I can actually do at the moment in its half-working state.