[Q] I am completely confused about the battery situation. Are there different
batteries, an extended and a normal? Is the extended battery a different
size/weight? Which of the batteries is this new standard size Duracell? Which
battery comes standard?

[A] They are BOTH duracell batteries, long and oval, with an indentation
running up one side. The mono (my mono 4/25 84 meg drive) came with the short
one, which only fits because of a plastic spacer. The compartment is 2" longer
than the battery. The extended battery fills the whole compartment.

[A] The color Aero 4/33c comes with the extended. The extended fits in the
monochrome Aero 4/25 though.

[C] Runtime estimates are variable, but it is a whole new world compared with
my Epson luggable. If you keep the light low, and don't use the disk much, you
can get 5-7 hours of continuous use with the extended battery. In practice,
though, you tend to get distracted, do something else. Then the Aero goes to
sleep. I used it on an all-day train trip without swapping batteries. 10 hours
of this sort of use is standard. I usually use the longer battery. The shorter
one lasts about 2/3 as long.

[A] The PCMag tests were pretty low usage; look at the sidebar regarding how
they did the tests. I wouldn't expect that long a life in real-world use. I
normally run my Aero 4/33c (with 12 meg memory) at "medium" battery
conservation, two to three hours at a time running AmiPro. The hard drive
seldom spins down and the display is on during (~100% brightness) the entire
time. I normally have around 2 of the five blocks still filled in on the
battery "status", or supposedly around 40% of the charge left. I haven't yet
managed to fully drain the battery through actual use (only by intentionally
turning off all battery conservation and letting it sit). Unfortunately, I also
haven't had the opportunity to time the length of time it takes to drain a full
battery.