First thoughts are it looks like a negative. Love the detail in the petals. You definitely need to darken down those highlights in the right hand corner as my eye keeps going to them instead of staying on the centre of the flower. I think this ties in with your question as to whether or not it is worth converting. Personally I would prefer to see this in colour in all its glory.
It looks like a negative because it is--the center was very dark.Yes, you are right about the bright spot. And the color was glorious--it was a red sunflower with yellow lines--I was trying to see if I could make it nice in monochrome. Guess not.