Hi Bombat,
I'd be keen to see a .15 or smaller model that flew well in a 4-2 mode. In my meager experience anything smaller than a .25 seems to be marginal if its not running flat out.
I reckon a .15 sized Peacemaker with the ASP .15 would be a real good thing running a fast wet 2 stroke on a good 8x4 prop.
Like you said, mimicking the FP .20.
Cheers Rob.