I think one of the biggest improvements is that when I need to take a break, my breaks feel productive. 20 minutes of cleaning the house, as an example, feels completely mind-clearing and, in some cases, actually helps me solve an issue I may have. I really enjoy my daily runs or bike rides, which help me feel like I'm more than just a developer, that I get to take advantage of the day.
That being said, I believe the biggest drawback is the monotony of the at-home routine. Some days and some weeks just feel like one large workday, and sometimes I can go for a day or two without saying a word to anyone other than my wife, or my cats. That's the greatest challenge for me. Working in a busy coffee shop probably appears like it would help the improve the feelings of isolation, but it oddly does the opposite. I see the same folks coming and going, day after day, and rarely do I get in conversations. And I'm actually quite social.
I don't think I'd go back to an office if given the choice, but I'm still working on the best way to feel less alone. I've been road bike racing on a team for the last few years and I believe having that constant outside-of-work social activity has helped quite a bit. For me, the cats are also huge! Plus, I just love cats. But there's certainly room for improvement and that's something I think about often.
I should note that I was hired to work remotely. My whole team is remote and spread out around the country.