Hello thanks everybody for your input.
Just would like to share with you my new understanding about the Budda's approach to upekkha, which is actually outlined in the Anapanasati sutta. After cultivating sila (purification of conduct) and samadhi (purification of mind), the Buddha taught us to contemplate bodily fabrications (breathing) and mental fabrications (feelings) to realize the anicca/dukkha/anatta nature of both bodily and mental fabrications, and then be mindful of the mind (presence/absence of greed/aversion/delusion) and gladden the mind to reach the jhana ("releasing the mind"); after the jhana is reached, contemplate anicca/dukkha/anatta of the five aggregates involved in the jhana to become disenchanted towards the five aggregates, and contemplate dispassion and ending of craving towards the five aggregates.
That's how one can reach not only anagami who has no greed/aversion (with upekkha), but also even arahantship.
Metta to all,
"Venerable sir, when this is the path and the method for the destruction of the five lower bonds for the sensual world [for some "bhikkhus"], why does a certain bhikkhu talk of a release of mind and a release through wisdom? Ananda, that is the difference in the maturity of the mental faculties."
"Whatever exists therein [jhanas or formless attainments] of (form,) feeling, perception, formations, and consciousness, he sees those states as impermanent, as suffering, as a disease, as a tumour, as a barb, as a calamity, as an affliction, as alien, as disintegrating, as void, as not self.
He turns his mind away from those states [jhanas or formless attainments] and directs it towards the deathless element thus:
'This is the peaceful, this is the sublime, that is, the stilling of all formations, the relinquishing of all attachments, the destruction of craving, dispassion, cessation, Nibbana.'
If he is steady in that, he attains the destruction of the taints. But if he does not attain the destruction of the taints because of that chandaraga (desire and attachment) for the Dhamma [those states: jhanas or formless attainments] then with the destruction of the five lower fetters he becomes one due to reappear spontaneously [in the pure abodes], and there attain final Nibbana without ever returning from that world. This is the path, the way to the abandoning of the five lower states."
--MN64 Maha-Malunkhyaputta Suttahttp://www.mahindarama.com/e-tipitaka/M