Rod Bucknell describe his experience:
It seems to be quite pointless state.The vipassana centre in Bangkok where I began my meditative training claimed to teach the system of practice developed by Mahasi Sayadaw of Myanma, often called Burmese satipatthana.
At the end of three weeks I was able to maintain uninterrupted mental one-pointedness for prolonged periods. During such periods nothing was present in consciousness but the meditation object, the sensations in the abdomen. The rest of the body, and the world outside it, had ceased to exist. I identified completely with the sensations: I was the sensations. Increasingly I experienced synaesthetic effects. For example, I often "saw" the pattern of sensations in the abdomen in various forms -- usually as an oscillating system of levers, or as a pulsating globe of light. On my teacher's advice I took this mental image as my new object of concentration. (The sitting practice had, by this stage, become the principal component of the meditative regime; mindful walking was now of secondary importance.) Then one day, as I was concentrating on my pulsating image, it suddenly disappeared, plunging me into a pitch-back emptiness. My teacher regarded this strange experience as an important meditative attainment, and told me to cultivate and prolong it. I followed his instruction for a time -- until I learned that the objective was to prolong the state of emptiness to twenty-four hours. The achievement of that feat would constitute successful completion of the meditation course.
At that point I decided it was time to leave the vipassana centre. I had begun to doubt the value of this state of mental emptiness, and of some of my other hard-won meditative skills as well. Thanking my teacher, I left Bangkok and moved to Chiangmai in the north of the country.
In Chiangmai I entered another vipassana centre, to find out if their methods were significantly different. There were differences in detail, but they amounted simply to different ways of inducing the same concentrated state.
Is it really aim / way of practise of Mahasi Sayadaw technique or widespread distortion of his teaching?