I got my Lumia 900 yesterday and am already frustrated that you cant toggle the vibration. It's not only loud but it will drain the battery life of you phone. I hope Nokia will include an off switch in their future updates.:D
Like the other "features," there seems to be a lot of variability. On my previous Lumia, the feedback was minimal and made barely any sound. On the one I'm using now, it vibrates very loudly. I am hoping for a fix for this, or the ability to turn off haptic feedback.