The SpyderCube
I have always struggled to get the perfect white balance when shooting using my digital camera. I thought shooting RAW would make things better. But all it did was slow down my workflow, and for the last couple of years, I almost exclusively shoot jpeg, even on my 7D. When it came to the X100 and the X-Pro1, jpeg was definitely the choice for me due to the superior on camera Jpeg engine Fuji had developed. The noise level from the camera coming straight off the camera was definitely better than what I could develop manually in Adobe Bridge, not to mention the almost perfect skin colour rendition.
But when it came to still life and studio lighting, getting the perfect colour maybe possible, usually using a grey card. The SpyderCube made this process much easier though. I shot the 7D in RAW, took the first frame with the cube on sight, and just cut and paste the white balance setting on the subsequent frames in my Aperture. Convenient indeed. And I was impressed with the results. Obviously helped by the new lightbox I had just purchased ......
Another worthy investment to be honest. I actually bought a studio set from Datacolor which contained the SpyderCube, Spyder4Elite and well as printer print colour analyser. I have yet to use the print analyser as yet. Indeed to investor a proper printer first however ......