There are pros and cons for each.

4-stroke
Higher Torque - Faster Response Time and Swings Larger Props
Greater Fuel Efficiency
Quieter
Nicer Sound - Subjective
Prettier - Subjective

2-stroke
Greater Power to Weight Ratio
Cheaper
Less Maintenance
Smaller Package

General Uses
4-stroke
Pattern Planes - Precision Required
3D - Throttle Response Critical
Scale - Nice sound

2-stroke
Pylon Racing - HP More Important Than Torque
Trainers - Easier to Tune, Kinder to the Wallet
Smaller than 30 Class Planes - Small 4- strokes tend to be too heavy in respect to power
General Flying/Budget - 2 strokes can be half that of 4's
Scale - To fit smaller scale cowls that would otherwise require cutting

Hope that helps!


And the plane I have is classic sport... fits a nice classic sounding engine.