It looks a little blocky to me if you know what I mean. I haven't seen the tutorial, but if I saw this (which I just did) I wouldn't think it was a real Mac wallpaper. You know what I mean? I'm not saying it's bad, 'cause it's not, but the general look of it is like someone tried to recreate the well-known Mac style of wallpaper. You did a good job with what you had however. Try something original that's all your own! It's much more fun and you feel better about it at the end because it's all your idea.
Yup, likeRubidox said, it's needs a bit more flow. Make the lines longer and more diagonal perhaps. Also add some more lighting spots.
