While there are plenty of things to point to in FO4 and note that it's broken, or been better, or whatever there is one thing I'm appreciating more and more while I play. And it's really something that the developers really didn't have to do, but they did, and it's pretty cool.
Note I generally play with my headphones on as my wife doesn't like to have to hear the game (she's generally watching TV in the next room) and I have a nice set of Beats headphones so the sound is really good. Plus they cancel out about all other sounds ... like my wife asking me if the trash was done yet.
Anyway the first time I noticed this was in Sanctuary. I was walking from house to house, just looting junk when it started to rain. I went inside one of the houses and immediately the sound of the rain changed to that of the sound of rain hitting a tin roof. It was a subtle change but I had to just stop and listen for a while. The immersion of imagining myself just sitting in that ruined house, listening to the rain was fantastic.
The next time was even more impressive. I was clearing out some building in town with Cait by my side. We exited on the rooftop at night and I noted a flash of light to the west followed by some boom and echoing explosions. Following that was gunfire from several directions. I just sat down in a chair next to a small table and just watched and listened to the combat and flashes of light around town. Cait finally sat in a chair next to me and we shared a bottle of Vodka I found.
I guess I could call this stopping to smell the roses (or gunpowder) but felt it worth mentioning that there are some parts in this game that are very immersive if you give yourself the time to sit back and enjoy it.