I think the key word every one is looking for is consistent power when it comes to glow engines. I use to fly all size ,except scale, electric planes. I never got into lipo's , to this day I feel they are to dangerous and can cause allot of damage to you your plane or even your house if you don't WATCH what you are doing.
As far as cleaning up goes , a wipe here and a wipe there normally does the trick for me. If your engine exhaust is pointed in the right way you can get away with allot of mess being left on your plane.
I'm been looking on-line and the electric planes look just as fun,
This is interesting , because I can have fun with a radio controlled robot if I had one, so IMHO this does't come into the equation. Radio Control anything is fun and will never stop being fun.
If I where you being I got into glow by accident , when I went onto a Hobby Shop and bought a trainer for dirt cheap, see if you can find a used electric of any caliper and find out if you can deal with those 15-20 minute flights before you have to swap out the battery. I hated switching and charging it grew on me fast.
GL
RCF esq.