Strengths of Process Thought
It clearly explains why a benevolent God would allow evil.
Religious believers can find comfort in the fact God suffers alongside his creation. This fits with the idead of God a sa suffering God.
If God experiences all evil in creation, there is reassurance for those who suffer that ultimately any struggle is worthwhile.
The fact that process thought has no guaranteed victory by God (unlike Augustine + Hick) encourages believers to actively fight evil and promote the good.
Weaknesses of Process Thought
God's omnipotence is clearly suggested in scriptures. Stephen T Davis points out that this is a teaching, not only suggested throughout the Old and New Testament, but is also one that is agreed upon by virtually all Christians. (can be found in Matthew, Psalms and Job)
Griffins' agrument is not a theodicy. By denying God's omnipotence, it seems Griffin is avoiding the Problem Of Evil rather than solving it.
A limited God is not worthy of worship. John K. Roth suggests that a God who cannot stop 10,000 Jews being killed each day, everyday for a year, in Auschwitz, even if he wanted to, is pathetic and unworthy of worship.
Maybe the suffering in the world is not worth it. God may experience all the bad and all the good, but some people only experience the bad so in this case the bad outweighs the good and isn't worth it.