I've now done some work with path text and it's quite usable once you get used to how it works.
However, one of the issues I found is that text "radiates out" on circles which means that you have readable text on the top, and ʇxǝʇ uʍop ǝpᴉsdn (upside down text) at the bottom if you stay on the outside.
I know this is probably a UI nightmare, but it would be cool if it was possible to insert some sort of switch in text so that ʇxǝʇ uʍop ǝpᴉsdn would turn 180º at that point and became readable text instead. At the moment, making a button that has both upright top text and upright bottom text requires two separate instances of path text.
There is, of course, every chance that I've missed something and you already have this somewhere. In that case, apologies and please tell me where it's hiding :).
Cheers, P