I've had my CX-3 from new for 2 years now, and I must admit it's the way it drives that really attracted me, apart from the great looks of the CX-3. The only slight downside is the space, as others have said, but this hasn't really been as much of an issue as I expected in long term ownership, you just learn to travel a little lighter, which is probably a good thing! There is a bit of wasted space in the boot (trunk) where the designers could have easily added some useful storage cubbies, but hey ho it is what it is.
As Diane pointed out there is a secret under floor space in the boot which can carry all your everyday things like bags, spare coat, de-icer etc, all out of sight and fairly easy to get at.
The only other slight niggle is that as mine is AWD you get 4 litres less fuel space because of the drive shaft to the back wheels, which knocks the overall range a little. Though I regularly get 330+ miles easily out of a tank with plenty in reserve.
The more I drive it the more I like it, it's definitely one of the best driver's cars I've owned, as satisfying to drive as my BMW 3 Series coupe was, it always puts a smile on my face!
Hope this helps you to decide.
CX-3 Sport Nav AWD 2.0 petrol Soul Red