Searching for advise on travel in Beijing

Hi there,
This is Hassan from Cairo - Egypt.
I visited Shanghai many times before and had very good times there.
This is my first time to visit BJ, i have read many travelers reviews and most of them had a very bad experience in the city.
I am reconsidering this trip and thinking to go to shanghai only.
Is BJ safe or not?
How can i avoid problems with Taxi drivers?
Is it worth to visit or not?
Please advise
Thank you