If you are a lousy worker with a bad attitude, your career path development will not be good no matter where you are.

To be honest, perfectly honest, career path development cannot be defined by the area where you are working in. You want a good career, you have to be a good worker whether it may be that you are working in Penang/KL/Johor or Terengganu.

For example, you say silicon in Penang/Kulim/Kedah. How many engineers are based there? 30,000? Maybe more, what are your chances of fairing against them who has so much more experience?

I guess you would need to re-define your question and provide more information especially which engineering field you are studying and what you are majoring in. If you study semiconductor and majoring in research with regards to III-V materials, going north and following the generalisation of a "better" career path there, you will be definitely surprised.