To my knowledge, all the Hyundais run just fine on regular. I’ve driven most of them including the R-Spec Genesis. Turbo is no different so far as I know. I believe the engines are identical to both companies. Probably transmissions too. It comes down to taste in my opinion.
This may be helpful.
http://www.thecarconnection.com/news/1075176_hyundai-elantra-vs-kia-forte-compare-cars
A turbo that doesn’t require premium is unusual, it’s an optional engine in the higher trim level Optimas, I’m unaware if it’s available in other models from even Kia, let alone Hyndai.