I must agree that is very nice to have such a long battery life on the Palm devices,
and I still use my PalmIIIc (color 160x160 8bit display) when I am going on long
trips, and also for general (basic) PIM functionality.
However, note that the battery-hungry circuitry such as the serial port is shutdown
when not in use, and there are many other power-saving techniques employed. If
you start comparing the batery life of LINUX PDAs and Windows Mobile devices,
you must take into consideration what is being done on them. If you start using WIFI
and listening to audio, reading/writing flash cards, have daemons running, etc., the
Palm Devices would also have a much shortened battey life.
I must also state how much I agree with the extremely high value of a polished
operating system. And also how much value the extremely well documented and
capable APIs were on Palm. I used 2.0, then 3.5, and only dabbled a little into
the 5.x successors. It became too much of a hassle to support software on the later
versions, since there were many differences (bugs) in the graphics operations, and
then the fork of Sony's graphics and audio APIs started to take the simplicity and
predicatability factor away.
Anyway, I'm done rambling!