After thinking about doing so for a few months, I finally signed up to go on a 10-day Vipassana meditation retreat in January. The retreat is very strict: no talking or any other form of contact with anyone inside or outside the center except for questions and lectures with the teacher at scheduled times, a strict regimen of meditation beginning at 4:30 am and ending at 9:30 am with no meals after noon, and they basically forbid you to leave (or as they say, "it is highly advised that you do not leave before the 10 days of the retreat are over'). I have been wanting to practice Buddhist meditation for a while and the challenge of the highly disciplined retreat seemed interesting. However, I am now having second thoughts.

Although the organization makes every effort not to market itself as a cult, I worry that during this strict, almost punitive retreat I will become vulnerable and easily susceptible to whatever ideas they want to fill my head with. These may be good, helpful ideas, but the intense isolation of the event is worrisome. I still have time to cancel, but I wanted to ask /adv/ first.

Has anyone ever been on meditation retreat? What kind of experience did you have?
Does this particular retreat seem legitimate?