Headless daily driver? Hardcore. What do you use for a browser?
I've tried it as a challenge for a couple of days (lynx, mutt, some other TUI stuff) and it made some things like Vim stick (although that may have as much to do with that challenge as Tridactyl did). But I couldn't last longer than a week. It does free you from the burden of system requirements. CPU: Optional.
> And my laptop battery runs for 8 hours
I imagine your display is almost entirely black for the majority of the time, with your (most probably) LCD backlight blasting away, trying its hardest to get a few thousandths of its light output through the few pixels on the screen that it can escape! XD
Brightness down, LAN card disabled (the media sense on RTL cards sucks about 1.5W with no cable plugged in, wtf? Thats more than the Wifi needs)
And powertop (great piece of software, thanks Intel) tuned to the max + powersave scheduler. All that on Windows or KDE results in about 4-5h of battery though. So fbdev must be somehow really frugal.
w3m can even display images in a linux console if you have the proper drivers or use KMSCON. It unwieldy but surprisingly usable. And my laptop battery runs for 8 hours which is quite amazing for a Zen1.