A few thoughts...
Regardless of the specs, numerous tests have shown the Mazda2's performance to be comparable with, or even better than, virtually every other subcompact on the market today. (Yes, the Honda Fit and 1.8L Nissan Versa are slightly faster, but neither is truly a subcompact.) So if you think the Mazda2 is too slow, then you're saying that pretty much any subcompact is too slow for you, in which case maybe you shouldn't buy one.
And it's ridiculous to say the Mazda2 would benefit from a 1.8L or 2.0L engine. That would just make the car too nose-heavy and would diminish the sprightly handling it's known for. The correct performance upgrade would be a smaller forced-induction engine, similar to the turbocharged 1.4 liter engine in the Chevy Cruze, which puts out 138 HP and achieves 40 MPG in a bigger, heavier car; in the little Mazda2, the mileage would be even more fantastic.
The Mazda2 does have a wide-ratio gearbox, which isn't the best for acceleration, but I prefer it over the Mazda3's close-ratio transmission. In my 2008 Mazda3 2.0L, I found myself constantly skip-shifting 1-2-4 or 1-3-5 because the ratios were unnecessarily close for everyday driving. And it revved at 2600 RPM in 5th gear at 60 MPH -- exactly the same as the Mazda2. That is actually on the low side for a small car; the Hyundai Accent and Kia Rio are whizzing away near 3000 RPM at 60 MPH in 5th.
And regardless of the EPA ratings, so far in my Mazda2 I've gotten 34 MPG in mostly city driving and 37 MPG in mostly highway driving, so it appears to be yet another car which easily exceeds the EPA's pessimistically low "readjusted" ratings.
