Originally Posted by 1967brutus

I think they both can do the job, but the FG21 might result in a pretty sedate flying style, and the FG30 might be on the wild side. Although I don't think it will be "grossly overpowered".
Weightwise, I don't think the 30 is that much heavier than the 21, and remember, you can fit a tank half the size of what is recommended for glow, so there will be a considerable weight saving there, at least "all fuelled up".
Had there been an FG25, then that would IMHO be the sweet spot.