Wikimartialarts

Here is a description of Cheng Hsin from the website wikimartialarts
To me it seems like a simplistic description:

Ralston used his experience in Karate and other striking arts to make a Cheng Hsin style which would enable its students to deal with Karatekas and other strikers.

It's suggestive that the author of the article may themselves be a Karateka. Its another interesting perspective.

http://wikimartialarts.org/main/index.php/Cheng_Hsin