Well I think the buying market in the US will be split up into three basic chunks: the urban/suburban cruisers (soul targets this group of buyers hard), the outdoor enthusiasts (Subaru has been going at this market segment for a long time), and the practicalities crowd.
I think the CX-3 is limited to the first group for appeal. It might make headway into the third group on milage, we'll have to wait and see. I think the renegade can cover a wider range of those three market groups than the CX-3. From the reviews, cargo space is probably it's biggest sin followed up by a cramped interior.
As for my personal tastes, I like the looks, but looking at the reviewers sitting in it, I can tell you right now I won't fit, not even close.