For me, there's never enough room on that questionnaire. I send an email to Couples when I get home that lists everything I would have put in the comment card and then some. I just keep the comment card as a reference when I send my email. I always get a response that it did get to the right location.
I did the same thing, forgot to hand it in. This might be a good place to ask if anyone has ever received 3 free nights fromt the questionair draw? Do they tell you that there is a possibly of winning three free nights to encourage you to fill it out? Has anyone ever won the draw?