gas:

cheaper fuel source
plane doesn't get as dirty
less fuel to carry to get long flights compared to glow
outstanding fuel consumption
fuel tank can be mounted on the CG becuse the carb is pumped
no need to bring a glow started to the field


if the plane can support at least a RCS 1.4 gas motor or larger the choice is very easy. Now if it can not thats a whole different story!!!

glow:

lots of power for the weight of the motor (certain brands)
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