What are the differences in belief regarding Hesychasm between the Chalcedonian (Eastern) and Non-Chalcedonian (Oriental) Orthodox Churches? I got into a discussion recently regarding the differences (or lack thereof) between the Oriental and Eastern Orthodox Churches.  I'm aware that the Oriental Churches are Miaphysites, while the Eastern Churches are Dyophysites.

My question is, has the above difference in Christology resulted in a difference in the understanding of the level of union with God a Christian can experience in this life?

A claim was made during the discussion I was in that the Oriental Orthodox Churches deny the it is possible for a person to enter into hesychastic prayer with God in which the mind, body, and soul are engaged in perfect, united prayer to God.  The Eastern Orthodox defend hesychasm as a central Tradition.

Is this claim actually true of the Oriental Churches?
As a Coptic Orthodox Christian, many of the differences between the two Churches results in the language and definitions of some key orthodox concepts. In fact, much of the Christology of both Churches is the same. 


  Hesychasm may be experienced by ascetic individuals, usually highly
  spiritual monks and nuns. Little is known about such matters as these
  spiritual individuals will not reveal this information voluntarily to
  anyone except their confession fathers, and their confession fathers
  will rarely expose this information until their timely repose.


Source

This source is from the Coptic Orthodox Diocese of the Southern United States and is answered by His Grace Bishop Youssef, the presiding bishop of said diocese