I do not know much about Coleman fuel.
Aspen is a highly refined part of gasoline, consisting of alkylates only. It hardly smells.
RON/MON 95/92, AKI ((R+M)/2) = 93.5 octane, which is extremely suitable for our model engines. Power is about equal to gasoline.
Because it is very pure, quality stays constant over time, and motors have less contamination.
Downside: combustion range is smaller than with gasoline, so needle settings are more critical. It is easy to flood the engine with choking.