I think it's less "going fast" and more "going fast forever."
To your point, you can blow through damn-near anything pretty quickly now. Now I actually find myself problem-solving for nearly 8 hours every day. My brain feels fried at the end of the day way more than it used to.
This. I’m able to be more productive for long hours more consistently than before. The occasions where I’m engineering for 8 solid hours are much more frequent now, and I’m certainly more tired. Almost all of my time is now dedicated to problem solving and planning, the LLM executes and I sit there thinking. Not everyone’s brain or project is well suited for this, but for me as a personality combined with the way my product is structured, it’s a total game changer.
Same feeling here!
I used to be like: "well, this thing will take me at least half a day, it's already 16:00, so I'll better do something quiet to cooldown to the end of the day and tackle this issue tomorrow". I'll leave the office in an regular mood and take the night to get ready for tomorrow.
Now I'm like: "17:30? 30 minutes? I have time to tackle another issue today!" I'll leave the office exhausted and take the night to try and recover from the day I had.