I disagree with the sound quality on the Vision:M, maybe it depends what you are listening to it through though. I really like my Vision, and the video quality is great, very good screen. I've compared the same video on my Vision and my friends iPod, and we both thought that it was certainly better on mine.
However, I do prefer the way the iPod looks, I must admit, I like the thickness. Given that, I'd still go for the Vision, the battery life on mine is better than Creative stated, I got four hours 20 minutes of video once on trains, after already listening to music, before it died. Scratches don't show up too much either, but definitely get something to protect the screen.