Before I'd buy an EXPENSIVE (read "YS"), fuel-guzzling glow engine that size, I'd sure take a long, hard look at gas.

Advantages of gas:
Adds free nose weight
Cheaper fuel
No flameouts on long approaches
No constant needle valve tinkering as the temperature and humidity change
No leaning out in tight loops or long climbs
Sounds more scale-like (4 strokes excluded)
The glow driver will never be dead
No worrying about tank placement
No exhaust "slime"

Disadvantages of gas:
Heavier
Slightly less powerful than the same size 2 stroke glow engine
Larger

Need I say more?

Dr.1