Let me preface this by saying I'm not a Kimchi hater (yes, it is necessary because this is LYN and this tered smells like something from /k). I actually like some of them, and considers the Ioniq to be a great bargain.
Anyway, Kimchi engines usually have higher, more impressive figures than their similiarly displaced peers, for example the Cerato's 1.6NA has 130hp while the Rio's 1.4l NA has 109hp. But the real world performance leaves alot to be desired.
Let's just say I personally take their official figures with a pinch of salt, no matter how impressive they are.
I don't think they cheat on their figures as HP and torque can easily be checked by dyno. It could be that the cars you mentioned have gearing which are tuned for economy so they won't feel powerful. It's like the ioniq on econ mode or sports mode makes a lot of difference but those cars may be permanently in semi-econ mode. For the Elantra Sport which is intended for power the gearing should be arranged for spirited driving. Using DCT is a reflection of that intent. Anyway the real proof is in test driving the actual car.