Can you comment on the value, positive, negative, or neutral of a ten-day (or some other number of days) retreat?
Meditation retreats are great opportunities to withdraw one’s attention from the world and direct one’s attention inward toward the self. Of course, from the ultimate perspective, everything is the self. But until one has completely neutralized all binding vasanas, one will still think that objects are real, still have decided preferences (i.e., likes and dislikes, desires and fears) that affect one’s sense of security, peace, and happiness, and still believe that lasting fulfillment can be found in objects. Consequently, the mind will be unable to maintain its “inner” focus in the midst of so many external distractions and will fail to recognize its true nature and abide it its innate tranquility. For this reason, it is important to take time each day to turn within and sit with the self, so to speak. Doing this for extended periods of time can be helpful, if one has neutralized one’s binding vasanas to such a degree that the mind is calm enough to afford one the capacity to sit still and sustain its inner focus. In such case, meditation becomes a ideal platform for self-inquiry. One is able to carefully observe the vrittis (i.e., mental modifications in the form of thoughts, emotions, and sensations) that arise in the mind and examine their ephemeral nature—that is, how they arise out of seemingly nowhere, abide for a time, and inevitably subside back into the unmanifest state. Guided by the principle that “you cannot be what you see” (i.e., the subject cannot be the object), meditation becomes an intense “arena” for atma-anatma-viveka, the discrimination between the self and the “not self,” which is the basis of Vedantic self-inquiry. Ironically, this intense scrutiny reveals that while objects are actually nothing more that modifications of consciousness, no object can comprehensively define or delineate that which is limitless and all-pervasive. Thus, the self is revealed as both the “substanceless substance” that is the material of which objects—both thoughts and, by extension, the entire manifest universe—are made as well as the “light” or consciousness that illumines the mind and enables the mind to know objects.
To reiterate, extended periods of meditation can be quite beneficial if one has neutralized one’s binding vasanas through karma yoga to such a degree that the mind can maintain its inner focus without too much agitation. If the mind is still unduly agitated by desires and riddled with anxiety over the circumstances of one’s life, then meditation will amount to little more that an internal MMA “cage match.” If such is the case, then it is better to cultivate the karma yoga attitude through one’s daily duties and shravana, repeated exposure to the teachings, until such time as the mind is sufficiently quiet and capable of engaging in quality internal investigation. Only you can determine this. Only you know if you can focus enough to engage in the discrimination between you and the objects arising within the scope of your being and, as a result, remain unfettered by the character of those objects. In this regard, it is important to also bear in mind that the goal of meditation is not a particular experience, for that which is non-objectifiable cannot be experienced as an object (i.e., mystical epiphany, transcendental state, etc.). The mind, however, should be quiet enough to allow for self-inquiry to take place.
Having said all that, there is no particular virtue or drawback to an extended retreat.
All the best,