Most auto journalists are going to like the Micra a lot more than the Mirage.
It makes me a little sad to say this, because I'm also a big fan of the wee Mitsu -- mostly because I'm a fuel economy geek who thinks the Mirage deserves respect for being the most efficient non-hybrid car you can buy here.
But having read & watched more than 150 Mirage reviews, I'm quite confident the Micra is going to get better press. Here's why:
1) The Price
Come on! $9,998 to start is a slam dunk marketing move. It has made some members of the Canadian auto press a little giddy, and they've already given this basic city runabout a ton of coverage. Even if most Micras end up costing more, it's hard to ignore the title of "cheapest car in the country."
Point of comparison: it's $2500 less than the Mirage's starting price (assuming Mitsu doesn't respond with a price change).
2) 4-cylinder engine
First, power: 109 horses are more than 74 horses. This will impress the average auto reviewer. More than a few have been unable to resist making jokes about the Mirage's 74 hp, even though the lighter Mitsu has an identical power to weight ratio as its only current direct competitor, the 4-cylinder Chevy Spark.
But 109 hp in the Micra -- the highest in the class -- will appeal to traditionally power-obsessed gearheads (who tend to self-select for careers as auto journalists). Even though Nissan's 1.2L 3-cylinder engine (which they use in the Micra all over the world) may make more sense in this car.
Second, engine "character": the Micra has four cylinders vs. the Mirage's three. 3-cylinder cars sound and feel very different from fours. Fours feel smoother, for one thing. Threes have a distinct "growl" under acceleration (that some people don't like), and they also vibrate noticeably at idle, which puts off a lot of reviewers. The Micra's four-cylinder will slurp down more fuel, but most journalists will overlook this in favour of smoothness and the familiar four cylinder driving experience. And the power... don't forget the power.
3) Conventional automatic transmission (not a CVT)
Many auto journalists hate continuously variable automatic transmissions. The Micra doesn't have one, and the Mirage does.
Even though a CVT is a lot more efficient than a "conventional" automatic slushbox, the CVT's driving dynamics aren't what most gearheads grew up with, so the result is many complaints about the apparent "disconnect" between engine speed and road speed. "Motorboating" is how some describe driving a CVT.
A CVT can also result in more engine noise under hard acceleration because the engine sits at a constant high RPM when the gas pedal is pressed to the floor -- not coincidentally, this is where many auto scribes have it pressed much of the time.
So, while the non-CVT slurps more fuel, it will generate fewer complaints from enthusiast-types.
4) Handling
Both Micra and Mirage are "world cars" that were designed to be sold in 150+ countries, many of which have roads that are in terrible shape. As a result, the suspension is set up to be squishy soft for a comfortable ride at moderate speeds over rough surfaces. They're not designed for taut handling at higher speeds on smooth asphalt.
This is one area where I think Mitsubishi has made a mistake: they didn't adequately re-tune the car's soft suspension for countries that have better roads and higher speeds. As a result, the car has been roundly criticized in the UK & US for having excessive body roll and unresponsive steering.
Nissan has learned from Mitsu's mistake: the Micra will be fitted with front and rear stabilizer bars for Canada -- the only country where this is the case. Reviewers who are more used to test-driving expensive performance vehicles than entry-level world cars will have one less thing to complain about.
5) Styling
Yes, this is entirely subjective.
But I think the Mirage's styling is inoffensive to the point of being anonymous. I'm not alone in this opinion: more reviews than not have commented negatively about the car's forgettable looks. Some have called it out-dated, and lots have commented on the "small" 14-inch wheels, which are arguably out of style.
Nissan faced similar criticizism about the styling of the current Micra (e.g. called "bland" in these UK reviews). As a result, it was "facelifted" just last year. And I think it worked: the facelifted car has more appeal than the Mirage. Nissan Canada has also made a point to note the car will not have 14-inch wheels, but will come with 15's as standard, and optional 16's. It's no work of art, and it's not nearly as aerodynamic as the Mirage, but I have a feeling it won't be criticized nearly as much as the little Mitsu has been.
Take these things all together, and when the media finally get their mitts on the little Micra, I think it's going to get a much better reception than the Mitsu got.