Putter, by 10 miles. I average between 15-16 GIR each round, with usually more than 30 putts. Could prob get to a +4 or 5 if I could putt/read greens. I don't even know where to start to get better at it. Missing as many short putts as I do kills confidence.
You should try the Whiteboard while you're at it. I like it more than the D+. Has some feel in the handle but it can still keep up with "scramble swings" pretty easy