At least in the sport flying realm, electric power is rapidly overtaking glow fuel power in all realms
of model aircraft - radio control, control line, free flight, as well as in helicopters. Beginning in
the mid-1990s, there has been an increasing number of competition classes that specify electric power
as well.
There are many advantages of electric power - much lower noise, consistent power, higher power-to-weight
ratios (using brushless motors and Li-Po batteries), no need to use fuel-proof finishes, no oily residue,
much lower vibration (allowing lighter airframes), less Volume required for most motor/battery/controller
systems than equivalent engine/fuel tank/servo system. Of course, some people love the noise and mess
from the traditional internal combustion engines and wouldn't give them up for anything.
Disadvantages include somewhat higher entry costs for electric, multiple batteries needed for aircraft
to avoid long downtime between flights, low noise level can make it difficult to tell if motor is running
at long distances (of course, if the airplane goes down with the throttle up, that's a good sign that
power has been lost).
I am going to collect some videos showing how successfully electric power has been.