I have been mentioned so here are thoughts.
If you need to be convinced to keep it, you're on the way out. Sounds to me like the wanderlust (Hyundai) is steering your ship more than love for the Fiesta. And that's OK. In the end you'll likely do all the planned upgrades you mentioned (which will make it far better than the Hyundai in question), drive it a bit, feel the same way before long, and eventually switch to another car. I had my Fiesta 7 years. I arrived at 304whp and 337wtq at year 2 of ownership. Was mesmerized and happy with that for the next 3 years. By year 5 of ownership I was starting to convince myself to keep it. Took till year 7 (last week) to finally say goodbye. It was never "not enough" - further mods wouldn't have changed my mind. Was just ready for a change. My power level was exhilarating every drive. But no matter how many Caramello candy bars you eat, eventually you're ready to try something different. In my case, when I first started looking elsewhere (at year 5) the clock started ticking.
I will say this, I've owned about 40 cars and the Fiesta is the one I kept the longest. Usually they last a year or two maybe. Seven was long. That says a lot about the Fiesta. Zero regrets selling though.
Good luck!!!