I wouldn't have thought the two cars would be on the same shopping lists, but more than a few members have said they considered the C as well.
EG: the Prius C has been also been discussed in these threads:
- What would your second choice be??
- The "Maikäfer" from Germany
- New Mirage vs Used Prius
- Intro Post (considered Mirage, Fiesta SFE and Prius C)
- Is there anything that might better the Mirage MT fuel economy in the real world?