In a consensual situation, do you prefer to be aware or unaware of an impending trance?
It really depends on the purpose of the situation.
I would normally prefer to be aware of an impending trance situation, particularly because of the sense of expectation involved. Plus, I believe that actively participating in the impending trance implies a deeper trance state and more satisfying trance experience.
However, in certain situations where part of the situation is dependent upon being unaware of an impending trance (for example, a surprise encounter with a friendly hypnotist who I previously gave permission to trance me at their discretion, of which there are a few, or to go a little more further, a pre-arranged fantasy scenario involving a mysterious hypnotist) then I would certainly prefer the latter.