Here is a short essay by a member of a fellow dharma forum titled: "Imitating Freedom: A Buddhist Refutation of Actualism". The paper explores the differences between "Actual Freedom" a.k.a. "Actualism", which is the teaching of a guy named Richard Parker who resides in Australia, and Ati Dzogpa Chenpo.
I am not posting the essay here for the purpose of comparing Dzogchen to a different view in order to say it is superior (or the other inferior etc.), but because the way the writer goes about making his points is well thought out and serves to address some of the subtle intricacies of the Dzogchen view. Primarily some of the notable differences between the nature of (i) the all-basis (or basis-of-all as it is coined in this paper) [skt. ālaya, tib. kun gzhi], (ii) the all-basis consciousness [skt. ālayavijñāna, tib. kun gzhi rnam shes] and (iii) the definitive view of primordial wisdom [skt. jñāna, tib. ye shes]. Focusing on how each of these aspects unfold (or in the case of primordial wisdom; may potentially unfold) in one's experience moment to moment.
The writer's argument is that the view of "Actualism" does not go beyond the all-basis, but according to the buddhadharma no other views or paths do (otherwise they would be vehicles of liberation), so this statement is nothing new. However the points surrounding this argument may be beneficial, as right view (whether inferential or direct) is an important aspect of Dzogchen and the buddhadharma in general.
There is no abstract (summary) for the essay, but here are the opening and concluding remarks:
"'Actual Freedom' or 'Actualism' is a fringe quasi-tradition which asserts an attainment of the same name. It utilizes methods intended on pointing out or bringing about a condition it calls 'pure conscious experience' or 'PCE', while it asserts all other conditions to be altered states of consciousness. PCE is an apparently non-dual and non-conceptual condition initially occurring for a brief instance prior to perception where there is an uninterpreted moment of pure sense datum, where the experiential continuum isn’t taken as an object nor are sense-objects being segmented and subsequently experienced as concepts, and where involuntary and recollective self-conscious memory imprints are not functioning, renewed, or newly created. During the course of repeatedly pointing out or bringing about such a condition (PCE qua path), the once brief instance is extended and then appears to stick (PCE qua fruit), and this apparently persisting condition is called 'actual freedom'. As implicitly implied by its name and by the terminology used, the quasi-tradition and its progenitor assert superiority and novelty over rigorously developed contemplative traditions such as Buddhism, referring to the Awakening found in Buddhism as mere 'spiritual enlightenment' an 'altered state of consciousness' while branding itself as a 'third alternative'."
"...'actualism' and its asserted freedom found in the the state of 'actual freedom' is not the true freedom of Rigpa, and it is devoid of meaningful novelty. It is evidently the base-of-all, providing no notable contribution to the science of contemplative theory or practice. Actualism tries to present itself as different, a third alternative, even an optimization, yet none of these claims have been demonstrated in the slightest. Actualism is a case of a distinction without a meaningful difference, and at that, a deluded path misinterpreting the base-of-all qua total relaxation, a path not capable of directly bringing about total freedom and even hindering the search and attainment of the freedom found in the supersanity of Rigpa qua fruit, the absolute total relaxation, the total completeness, the supreme happiness, ultimate satisfaction, and end to existential lack and thus a total plenitude. In the face of Rigpa therefore, it is a mere imitation of freedom."
The paper can be downloaded directly from this thread, or here is another link to download the essay via scribd: