Daniel M. Ingram:
Is the Theravadan system the only one that creates steps?
Definitely no. The Tibetans have many maps (5 Paths, some number of Bhumis (often 10, but there are other listings)), there is a Dzog Chen tradition I just heard of 2 days ago with 52, apparently, there are numerous Zen masters who describe various stages of their realization (Chi Nul had 3, some other big Zen guy whose name eludes me at the moment had about 17...).
Then we have the people who just seem to have jumped there instantly. We also have the people who trained very hard in some tradition (e.g. Adyashanti), realized whatever (or not, e.g. Andrew Cohen?: just not sure what to make of that guy...), but then advocated that their followers not train the way they did, but just realize they were already enlightened or that there is nothing to do, or whatever (this later group tends to annoy me the most...).
It is hard not to be inspired by some of the heavy spontaneous realizers, such as Nisargadatta, Poonja-ji and Ramana Maharshi. They tend to be very impressive, and their teachings can be very impressive. I have some of the published works on them and by them and found them compelling and insightful. It is very hard for me personally to doubt that they have profound insight and experienced real transformation.
I like what you said there. Just a few comments... with regards to Advaita, there is a difference between traditional Advaita and neo-Advaita. Traditional Advaita is where sadhanas are being emphasized, including primarily the practice of atma vichara or self-inquiry which leads to self-realization. This is taught by Ramana Maharshi as the main method of practice. This is also taught by Adyashanti, who teaches primarily 1) self-inquiry and 2) sitting meditation (http://www.amazon.com/True-Meditation-Discover-Freedom-Awareness/dp/1591794676/ref=pd_sim_sbs_dmusic_a_1) as self-inquiry led to Adyashanti's awakening as well. For myself I also practiced self-inquiry and it has led to some important realization. For Nisargadatta, he practiced "holding on to the sense of I AM" as instructed by his guru for two years until he had self-realization, then in latter years he also speak about the "nothingness" which transcends or stands prior to the "I AM", etc. He basically guides students to "I AM realization" first, then when students got there, he guides them beyond it into "nothingness" (clear indication of some form of 'stages'). He also advise people to do those practices including "holding on to I AM", self-inquiry, and so on. Then there are some (traditional) Advaitins like Michael Langford that even advise people to meditate at least, minimum, 2 hours per day and says that he sits 12 hours a day on most days for two years before self-realization practicing 'awareness watching awareness'. Thats kind of extreme and I don't think that much sitting commitment is necessary for realization but I believe Michael will have very stable experience and samadhi apart from realization.
It is particularly the Neo-Advaitins like Tony Parsons that emphasize the whole "no practice" "no meditation" thing... and this is criticized by many traditional Advaitins.
Dzogchen's Thodgal path has four visions, 1st two visions are pre-bhumi stage (although by then one has already recognized the unconditioned clarity aspect of rigpa, as distinguished from realization of rigpa in full), 3rd vision is where emptiness is realized and corresponds between 1st to 7th bhumi, fourth vision is 8th~16th bhumi (info source: Loppon Namdrol/Malcolm Smith, who is asked to teach Dzogchen by Kunzang Dechen Lingpa who is a 'fully awakened Buddha who accomplished four visions' Dzogchen teacher). Fourth vision is where you attain the goal of Dzogchen: attainment of rainbow body. What is rainbow body? Malcolm explains: "KDL went though all four visions to the end. He told me this personally. Not only me, but others. He did realize rainbow body. Rainbow body, in Dzogchen, does not mean that your body disappears. This is a huge misconception....it is stupidly simple -- once you reach the end of the fourth vision, everything is a display of the five lights, as it is put in the classical text earth, rocks, mountains and cliffs vanish and instead one sees only the five pure lights.....In other words, rainbow body in essence is actually a realization...." - http://awakeningtoreality.blogspot.com.au/2013/03/rainbow-body-and-thusnesss-advise.html
Of course, from another perspective, Dzogchen also say things like
"There are many meanings to the term "non-gradual path". The most important of which is, if one understands the state of one's natural primordial condition, all the 13 Bhumis of Bodhisattva, whatever 7 stages of enlightenment, 4 or 5 of this and that etc are subsumed. The relative manifestation of each of the divisions, stages etc may not be apparent, however. Yet, that understanding, the ultimate, encompasses all. That is the most important meaning of in Dzogchen of being non-gradual. The analogy of the eagle in an egg is always given to signal that once a practitioner breaks free of the shell of the physical body, it will fly - meaning will manifest the complete potential of a realised being beyong the considerations of 13 bhumis etc etc." (Cheh Goh, SMS teacher in Chogyal Namkhai Norbu Rinpoche tradition) Namkhai Norbu Rinpoche also teaches about the four visions because it is central to Dzogchen teachings.
Practically speaking, almost all Dzogchen practitioners go through those stages however. There is the understanding based on "spontaneous perfection" yet there is no denying of 'maps' or 'stages' in Dzogchen teachings. The same also applies to Zen, generally, where the five ranks of Tozan and ten oxherding pictures, etc are taught. In other Tibetan traditions, there are other maps as well, such as the four yogas of Mahamudra, 13 bhumis, etc.