I actually did the same a couple weeks ago. then, I took a break and by the time I was ready to start "finishing" DRG, double CP ended, and I don't think I can stand that monotony again without it.
Got 550 on THF myself, got my WHM mule to 550 at the same time, CPing together, that sort of jazz, capped her at 200 spare for the eventual increase to 20JP per category.