Louise, my main issue was the gridded questions (“How important are the following aspects of a conference?”, “Which of these topics…?”, “Which of these technologies…?”). It was tough to follow which row I was on when filling out the appropriate radio button.  Maybe adding some zebra-striping or some horizontal bordering would help. A hover state on the row would help a lot too.  The problem is intensified with it being a fluid page. If you  view it in a maximized window on a large enough screen the responses become too far apart from the actual field they are attached to.

I’m sorry, I feel like I’m probably nit-picking a good bit. It was just a little frustrating when filling it out and if I found it to be that frustrating, I imagine others might feel the same way and not bother to respond, which I’m sure is not what you want. Not sure how much customization you can do through Survey Monkey, but I would recommend looking into these things for your next survey.