Looks like it takes around 4 seconds to get from just over 100 km/h to a dead stop. Seems like a long time to stop in an emergency situation but then again you are supposed to keep a 3 second distance between you and the car in front of you. The Niro may not be stopping fast enough to avoid someone hard braking in front of you but it could reduce the chances of injury with its stopping power.
When it comes to an SUV like this, all that really matters is that it can get up to speed at a good momentum in line with the flow of traffic and better and that overtaking other vehicles when required is easy enough.
You guys can always look into the Mazda CX-3 if the Niro isn't fast enough.