I hesitate to discuss this issue, but nothing ventured nothing gained.
I have read many of the critiques of Piper's form of Christian hedonism and although I dislike the term hedonism because of it's connotations with secular hedonism.
However, I must say that because I have read some of Piper's material on the subject as well as watched a DVD on the matter.
It seems to me that most of the critiques problems seem to stem from a misunderstanding, that Christian hedonism is based on pleasure being more important than God. However, I do not see that as what Piper is saying at all.

For example take the following dialogue from Wikipedia.
Some evangelical Christians object to Christian hedonism's controversial name[3]. It has little historic commonality with philosophical hedonism, however; Piper has stated that a provocative term is "appropriate for a philosophy that has a life changing effect on its adherents." Critics charge that hedonism of any sort puts something (namely, pleasure) before God,[1] which allegedly breaks Ten Commandments' first order: "You shall have no other gods before me." In response, Piper states in Desiring God that "By Christian Hedonism, we do not mean that our happiness is the highest good."
In a nutshell, Christian Hedonism means (in Piper’s words):
God is most glorified in us when we are most satisfied in Him.