Lot of good experience and opinions here. My experience was I went with Crutchfield recommendations in my 2011 and replaced the center speaker, front tweeters, and front door speakers with their recommendation. I also installed a Kicker HS10 on top of a plastic tool box in the rear.
My OEM center front speaker and front door speaker cones were definitely dried out and "fuzzy" in my 2011 (replaced in 2022). The sound after the speaker upgrade was MUCH crisper. The subwoofer in the rear filled it out. I had also replaced the OEM radio with a Jensen CAR910W for the wireless carplay. Overall the sound was excellent. I initially did not replace the tweeters but after the improvement with the other speakers I replaced those and the highs were much brighter. I suppose over time they had become dull.
Now in my 2019 the overall sound is "great" but I was listening to Nillson's Jump Into The Fire
https://www.bing.com/videos/rivervi...249834D1AF05D2B753AB249834D1AF05D2B&FORM=VIRE recently and the bass sounded like it was in another room during the recording. So I temporarily installed my HS10 in the rear to bring it up but it has been disappointing. I am still experimenting. I don't have it mounted to the old plastic tool box which I may do. I do need to get my phase tester out and test the OEM speakers for phasing. After listening to our previous 2013 Pathfinder for many years with it's lackluster sound system I tested the phasing and found that two of the 7 (or 9) factory speakers were out of phase from the factory...
Good luck! Let us know how it goes! Changing the speakers and head unit is not hard!