I'd argue that glow engines are simpler and once tuned easier to maintain.

Glow engines do not require ignition systems, pumps, diaphrams, float bowls, etc. some of which wear out or degrade even if the engine is not in use...

That said, gas engines can be very economical.

By weight, glow engines produce more power, so you have to load a plane down more to get an equivalent amount of power output, which negatively affects performance.

The upside is gas is CHEAP compared to glow fuel, and gas engines run reliably once tuned.

Glow fuel stores VERY well for very long periods of time, provided it is kept in a cool preferably dark place. The key is to keep the container sealed until you are ready to use it, and once opened finish with that container within a reasonable amount of time. I've run glow engines on fuels which are over six years old without a single problem.... I've also have had glow engines out of service for 3-4 years ( with afterun oiled applied initially and enclosed in a baggie around the cowl... ) that start up without a hitch.... usually if a gas engine is sitting around this long, I'd have to rebuild the carb... though the latter is not difficult given a repair/rebuild kit.

For me what dictates the engine is the size of the plane.

Normally for planes in the .90 size range and below I go glow or electric.

Planes above 1.40 in size it's usually gas, as long as there is not an overriding reason not to...

In between it's a toss up.