I bought a Note 4 about a month ago after getting some hands-on time with it and the S6. It has been fantastic. The screen is incredible and the battery life is outstanding...but I had no idea how outstanding until today.
I was at a client location all day in a meeting today. I had my laptop, but could not connect to the client's network, so I put my N4 in hotspot mode and used it to VPN my laptop into my company network. Unfortunately, I forgot to bring a charger. I didn't think it would make it through the day, especially since I used the N4 pretty much non-stop on the 90 minute train trip to that location. It not only lasted through the entire day as a hotspot, I still had about 35% battery left when I got home after the return trip on the train.
It is a beast.