I found online (thanks coolmel!) some of the objections of Grof to Ken Wilber's theories - although the objections might be more applicable to "Wilber V.2" or "Wilber V.3", rather than Wilber V.5.
For all psyche majors out there, that might have been able to take classes in full spectrum (transpersonal) psychology (cough Ryan cough), has this particular gentleman's disagreement been resolved?
Also, The Primal Psychotherapy page is a great resource for full spectrum psyche fans out there!