David is an outstanding teacher in his theoretical teachings.
I have noticed that he is very accurate, and gives an extra attention to prevent devotees from stumbling upon common spiritual traps. One of the most common traps of spiritual seekers is impatience, which easily leads to unrealistic expectations of the mind, and consequently to a spiritual despair. David keeps reminding about the gradual nature of the awakening process, and the fact that enlightenment does not happen over night.

In parallel to my Self Inquiry process, I'm enganged in mathematical research. I find these processes very much similar (though the tools and goals are different). During research, most of the time there is a contemplation regarding the problem, without seeing anything new. Once in a while, there is a little breakthrough. After a certain amount of breakthroughs there is a discovery, after which you see the all picture, and have a full knowledge of the subject. You then realize that the picture was there prior to your discovery, but you couldn't shorten the process. All the wrong ideas were also essential (as an elimination), and in fact a part of the process. When one applies to Phd, her mind is usually ready for the process. She (or he) knows that it would take 4-5 years for results, and does not expect to finish it within one week. This is critical in fulfilling that goal.

However, the spiritual realm in more chaotic. There are some teachers, like Tony Parsons, U.G Krishnamurti, and many others who say that "there is nothing to do". It can be helpful as an inspiration, or for certain seekers in a certain level of spiritual process, but for others it creates a confusion. There are also famous stories of sudden awakenings, without any former practice, like those of K.Byron and A.Tolle, and even R.Maharshi. These might add to the confusion as well.

Personally, I'm experiening the gradualness of the process of awakening. There is a slow change in the level of consciousness over time, which takes over my being. The Self Inquiry process is the most direct practice. Not knowing who you are is the core of the problem, and observing your self/Self is the reasonable way to clarify this confusion.
Since I've met David, this process accelerated significantly, and sweet Bhakti was also added to the process.
Gradual does not mean "linear". It is likely that some other "quantum leap" or grace are needed when one is ready for the consciousness to take over his mind, but it seems that a thorough preparation can allow it to happen.

Deep gratitude to David, my beloved divine teacher.