Nancy - as you know we very much enjoyed our Crystal cruise in 2006. The signing just wasn't an issue, nor was the fixed seating, at least not for us - but then we did luck out and have a great table, and we ate at the alternatives a couple of times each, so it worked well.
Have a wonderful time - as I know you will. Are you doing the TA that gets back to Miami on Nov 19th? I had some clients very interested in that one, but then one of the couples kids got pregnant and they wouldn't go and miss that, so the other couple opted out as well, since they usually travel together.