I also replaced my front center speaker on my 2014 Grand Cherokee Overland with the Polk DXi350. Wow, easy to do and it make a big difference. The Polk has more high-mid and high range. The stock speaker is very muffled sounding.
I did a quick video to compare the difference. The stock speaker sounds louder and maybe better for voice in this video but I assure you it is not better. It only sounds like this in the video due to the crappy iPhone recording. But this video does help you hear the addition of the high frequencies in the Polk. Trust me when I say it sounds better in person than in this video, but you can get the general ideal.