I think it's quite good. You really captured the texture of the petals and the white blossoms add interest to the rest of the frame. The only thing I don't like is the mid-far right edge where that leaf comes to a point. That bothers me.
I think the rose it self is killer. Like Bazooka said you can feel it in this picture. What I dont like is for some reason my eyes are drawn to the extreme darkness on the bottom of the photo, under the rose or on the bottom part of the petals. Now I dunno if it's my comp or not but thats the one thing from me. I'm gonna take a guess here on what one of the better experts would say but I think if you used fill flash that would have gotten rid of that problem. But this is a nice shot I do like it.