Greetings from the Critique Club:
Challenge: With the rose being off-center in this picture, you definately met the challenge criteria. However, I would like to add that you did well with the positioning besides just putting it to the side of the picture to meet challenge. Which takes me to the next section of my critique.
Composition: I like how you kept the leaves of the rose in focus and a part of the composition. It frames the picture nicely and adds to the total depth of the shot. It also gives it a feeling of completness. I was thinking this rose was from your own garden, but in any event, the rose is nicely formed and you chose a nice one to put in your photo.
Technical: The colors are very nice. The only thing that I might suggest is pushing up the saturation just a bit. It would help the colors pop out just a little more. The lighting is appropriate as there is no annoying glare or "hot" spots. You focus and DOF is absolutely wonderful. I would not change a thing in that area. I especially appreciate seeing the detail in the rose, such as the veins in the petals and leaves. As I mentioned above, I like how you kept the leaves in focus. I do agree with one comment...about the white spot at the top left. Too bad about that, but after the challenge, you can clone that out.
Overall: I was looking through some of the other photos that you have put in for challenges and I do believe that, in my opinion, that this is the best one for you. This rose is beautifully done. I do believe that you could have scored higher with this picture, however, it is considered a cliche shot on DPC and I find that voters keep the scores down for such shots. 20 out of the 124 votes that you got scored you a 4 or lower. No way did this deserve these lower scores since it meets challenge and is technically well done.
Keep up the good work!