The first year for the Mazda CX-3 was 2016. Did you mean the discontinued CX-7? CX-7s with the turbo engine are notoriously troublesome. The non-turbo should be reasonably reliable, though.
If you meant a Mazda3 hatchback, I'd look for the current one (2014 or newer).
You might really like the driving position and solid feel of the Ford C-MAX. My concern with the C-MAX would be the long-term reliability of the powertrain. But the Ford Fusion Hybrid has had this powertrain since 2010, and it has been reasonably reliable so far. Fuel economy tends to be mid-30s US mpg.
I also often recommend the Ford Focus for people who'll be buying a manual (the automatic transmission has been a problem area). But it's less roomy than the C-MAX and might feel too cramped for you.
The Elantra Touring does have more room and better outward visibility than other recent compact hatchbacks. Any idea which trim level you test drove? I tested the uplevel trim, with the 17-inch alloy wheels and leather, and don't recall it feeling especially light. If you didn't test this trim, maybe try to find one. (I do agree that the Matrix feels like a tin can. Not Toyota's best effort.)
Among compact hatchbacks, the most solid-feeling is probably the Volkswagen Golf. The current generation, 2015 and up, handles especially well. You might really like how it drives. But long-term reliability is more iffy than with the others. Most are fine. Some are bad.
Have you considered a newer Subaru? The current (2014 and up) Forester has excellent outward visibility and feels pretty solid. Too large maybe? Subaru also offers the Impreza and Crosstrek, but I haven't driven either recently. The 2017 Impreza looks very promising, but probably out of your budget.
Lastly, you might like the second-generation (2014 and up) Kia Soul. A problem with these: if you want a manual transmission, one has only been offered on the base trim with the smallest engine.