I use my iPad mainly for media consumption. However, one of our lead engineers here uses his iPad for taking notes and sketches during meetings. I have my plethora of notebooks, depending on the program, he has one iPad and does everything on that.

I was down on a production (or destruction I guess) line looking at parts that were questionable with a couple other folks. One guy had his iPad and was taking notes and pictures directly with it to keep everything in order. The rest of us relied on pencil drawings, copious notes and descriptions and a dedicated camera that we'll have to use to integrate all that stuff into a single document. I think his productivity (and the lead engineer's here) was probably enhanced quite a bit by their iPads. It really depends on what you want to do I guess.