I have Yaris Ative X and all the things you wrote above are true.
And its sport mode makes a car bit quicker but it can never ever do 0-100 even in less than 12 sec .
Car is pathetic in terms of acceleration.
When ever you try to over take someone and give car a little peddle it makes sound like you have done some kind of ziaditi with it. Very very sluggish car in 1.5 category