Q. Is Kia Sonet 7dct gtx good for hills?

Kia Sonet offers oodles of performance and the car would not poise any issues while driving up-hill. Moreover, the GTX Plus Turbo DCT variant comes equipped with features like hill assist, electronic stability control, vehicle stability control system, etc to make your drive safer.

No, it's not meant for hilly roads with incline all the time. the transmission system gets over heat if continuous use for hill climbing and the engine is not powerful enough for hilly roads. I have the gtx plus petrol, it struggles in steep climb and does wheel spin also. I prefer my manual car if I am to go to hilly areas.

I haven't faced any issues as @Hormett said. It's been 2+ years and 16k+ kilometers and been to hilly areas and ghat roads even with 1-2 hours of bumper-to-bumper traffic and never faced overheating or any other issues. Probably it's the driving style!