Chinatown is an excellent food and shopping destination (especially for those who are looking for luxury brand look alike products). For me, it is more a food and cultural attraction.
Although many aspects of Petaling Street has evolved to cater to tourists, take a closer look and you will find shops, food outlets and pre-war buildings that has remained unchanged for decades. It is also where you can find some of the best Chinese food in town. How do you find them? Just follow the locals. If it is packed with locals, it is usually good. Just point to the next table to order if there is a language barrier.