It would be interesting to hear from someone who had extensively practised in Goeka-ji retreats and also Mahasi-style retreats whether Goenka is really addressing the same thing.
Certainly the sequence described in the Visuddhimagga, and summarised by Mahasi Sayadaw http://aimwell.org/Books/Mahasi/Progress/progress.html
5. Knowledge of Dissolution (bhanga-ñāna) http://aimwell.org/Books/Mahasi/Progres ... issolution
as following on from other stages, in particular Knowledge of Arising and Passing Away (udayabbaya-ñāna)
The question in all of this (which I have no idea of the answer) is how linear it is. Sayadaw U Pandita characterises this progress as "Vipassana Jhanas" http://homepage.ntlworld.com/pesala/Pan ... hanas.html
Talks by teachers such as:
Joseph Goldstein http://www.dharmaseed.org/teacher/96/?q ... ana+jhanas
Steve Armstrong http://www.dharmaseed.org/teacher/170/? ... ana+jhanas
seem to describe these as things one can cycle up and down through, not necessarily a linear progression.
My impression (and minor experience) is that the Mahasi-style instruction does tend to give a reasonably linear progression (though one definitely tends to "fall back" at the end of a retreat) that seems fairly in line with the observations in the Commentaries of how the progression happens. Perhaps other techniques lead to a slightly different progression.
Certainly I had that "body disappearing" thing on my only Goenka retreat three years ago (and it was quite disconcerting at the time ---not just some little hint, it really felt gone...). With the Mahasi technique that I normally use I haven't got quite that effect. I do, however, get what I sometimes describe as "objects breaking up as if under a flickering fluorescent lamp" effect instead... I put these differences down to the way one is taught to pay attention under the two systems.
As you can see from the non-technical language, I'm not an expert at either of these systems. I would be interested to learn more without the discussion descenting into negativity about either practise.