For perspective, I'm a 27 year old married small business owner who loves dogs and rallying. I owned this car for six short months, but I completely fell in love with it within that time. It was nearly perfect for me.
Besides the obviously underwhelming low end torque of the 1.6l engine, there is nothing to criticize here. In fact, there is a lot to praise! This little car has the best suspension tuning I've ever experienced, even beating an A3 when it comes to reactivity (I know I'll get flamed for this, he he). In fact, it's so responsive that the first time you get on after driving other superminis (actually, almost anything short of a hot hatch or true sports car), you'll probably find yourself turning in waaay too early for an hour or two. For a budget car, it's impressively capable: so precise you can actually brake hard from 140km/h to 40km/h around a "unseen 4 left over crest into speedbump" without feeling any danger. Gravel roads are a lot of fun so long as they're not too steep =). Even the pedals are spaced so you can use heel-toe downshifts (well, if you have feet like mine at least). Only gripe is the steering could use a bit more feedback.
Some people might find the suspension tuning a bit hard, but I'd rather have my eyeballs liquefied over a cobbled path than feeling seasick after a couple of km of moderately twisty road. As I said before, driving the car is so much fun that you have no time to notice a few bumps here and there. The seats are good, space is ample (I had a 2-door version). However, on this department is where I had my two biggest complaints.
The first is that gears are hard to engage at times: there's some kind of restriction midway between neutral and every gear that makes you think it's engaged when it is not; as a result, expect to miss quite a few shifts in the first few days.
The second, and probably most important complaint of my whole ownership experience, is that the clutch engagement point is too far back and extremely sudden. This means that one has to press the pedal nearly all the way to the floor to disengage a gear, and putting the car in motion either forwards or backwards is very difficult. Heck, it's so hard to start that three out of every four valets stalled the car at least once while parking it, and at least half of them did so repeatedly. But the most serious consequence is that, if you're like me, after about three or four months of driving it you might start getting lower back pain on you left side; I did, and was clueless as to why, until my orthopaedist traced it back to repeatedly exerting excessive force with my left leg fully stretched. Kinda like deadlifting without a belt, but only on one leg; one day I simply couldn't get up and out of bed, and it only went away when I stopped driving the car. It's probably something to do with my proportions, as I've had different posture problems with cars that others say are perfect, but it means I would never buy another Yaris unless there is a solution to that problem.
I personally like its looks very much. I think it's a nice compromise between target customers, as most girls seem to like it because it's "cute", and other guys like it because it's "cool". Blue and red look great.
For a married couple with dogs, this car is just perfect. Ample space in front, and with fold flat rear seats, the back swallows an awful lot of load. In my experience, it became obvious that this car was designed with two people in mind, as four people with three day's luggage, or five people with none, will have the car bottoming out on speedbumps (of which there are millions in Mexico).
RELIABILITY AND SERVICE
This is where the little car really shone. I really beat it up: a thousand kilometers of steep, rocky gravel roads; engine braking, heel-toe downshifting and traction limit cornering on every last bend; days and days of highway driving; no mercy for the dampers on potholes; taking relatives for a few spins at sandy football fields; absolutely no braking for water splashes; taught my wife how to drive manual on it... you get the idea. I had absolutely no problems with it at all. Mechanics said that there was no abnormal wear on any parts (including the clutch), engine worked perfectly and started instantly no matter the heat or cold, dampers worked very well, and no part ever rattled or made so much as a strange noise. Commendable.
Were it not for the clutch engagement thing and my proportions (a problem I don't think many people will see), I would not hesitate about getting another for my next car.