2 stroke and 4 stroke belongs to two different classes, they have different riding pleasures, different feel, sound and smell. CG125 is not a latest tecnology bike, its from 1970's technology just got cdi in 1992. GTO125 came with cdi in 1988. So its not the question of new and old technology, 2 stroke engines are still in use around the world where light weight and more power is required, but the engineers now a days working on more environment friendly 2 stroke engines. CG125 has got good sound, comfortable ride, more day to day practicality, but where comes the sling shot races, CG125 or GS150 has no match with RX115 or GTO125