Had a chance to compare both models today.
The Fit is very cute for what it is. I liked the size and seating position. Definitely a lot of space inside the little guy.
However, the HR-V feels like a luxury car in comparison to the Fit! Doors feel heavier, seats feel thicker and more supportive. The seats on the Fit were quite thin and did not seem very supportive. Interior finish is much better on the HR-V. Visibility on the Fit is significantly better than the HR-V obviously. The HR-V "feels" safer but that's just largely due to the size and heft. With that said, I certainly didn't feel like the Fit was a tin can in any way.
I like the little touches on the HR-V like lighted vanity mirrors. Space inside the HR-V is more than enough; trunk is huge, rear seats have ample space.
Both of them are "economy cars" but the HR-V just seems more solidly constructed and more substantial. For ~$21k you can get a loaded Fit (leather, navi, etc.), and for ~$22k you can get a HR-V EX, which is the best value for money, IMO. (I don't think leather, navi, and an auto-dimming rearview mirror warrant the ~$5k increase between the EX and EX-L).
I originally was thinking of getting the Fit, after today I have to say the HR-V wins by a landslide. The HR-V is the perfect size for someone looking for something in-between a hatchback (Versa, Fit, etc.) and "regular" CUV (Rav4, CRV, etc.) Gas mileage difference is negligible to me, although it seems Fit drivers can get 40+ mpg on a regular basis.
(not my pics)