I think that the new transport system is better than the previous one, known as "micros amarillas" ("yellow buses"), mainly because it's cheaper, cleaner and friendlier than the old system.
Transantiago can be considerated as a real system, where all the buses and the Metro (Santiago's subway) are interconnected, not like the "yellow buses" which were only a conglomerate of privates enterprises that competed between each others, converting the streets of the city in a big chaos.
But, this changes cost a lot of problems for the people and for me, becauseat the beginning (one year and some months) of the implementation of the system the situation was terrible. I live very far from my University, and the Transantiago each day caused troubles to me and millions of people. The worst was the long waiting times for the bus to arrive, the slow trips and extremly crowded buses, and the long time required to get home.
Fortunately the system changed, maybe very slowly, but the important is that it changed. Some things continue failing, principally the crowded subway in the peak hours, and the lack of buses in regular hours.
I hope that with the new lines of subway, and more feeder buses, the system will work perfectely well.