My personal taste: if you assume that head capacity is limited to some product of displacement (obtained by stroke change) X RPM, I'd rather use the longer stroke and keep the RPM down. Many $$$ worth of valve springs last another season, etc.
The math: stroke length X +10% increases displacement by (duh) 10%.
Increasing peak RPM by 10% gives the same product, but increases inertial load by 110^2, or +21%.