In an attempt to improve my tripod setup I just bought an Acratech GPS ball head on eBay to replace the Benro B1 that came with my travel tripod. In the process I have discovered a problem that is common to both of my two GX7 bodies: With the camera on my big 3-series Gitzo, well clamped down, and with everything tight, I zoom my 14-140mm to 140 and look at a lens test card that is across my shop. Attempting to wiggle the camera by wiggling the Arca clamp or anything else below the clamp produces almost no motion. Wiggling the camera body or, worse, the end of the lens produces big changes. When the balll head friction is set to barely hold the camera from flopping over, any attempt to adjust the center point of the image by moving the camera body results in the body flexing and rebounding when the movement pressure is released. Even at the 140mm zoom it is enough to be a problem. I dread doing the same testing with my 100-300mm. Bottom line, it appears that the tripod screw base in the camera is not solidly connected to the lens flange. Naive guy, maybe, but I would have expected that tripod socket to be machined into the same block of metal that comprises the lens flange. A partial workaround is to aim the camera by gripping the Arca clamp, putting no pressure on the camera body. The floppy body, though is probably the reason I have seen a small shutter shock effect when testing on my Gitzo 3-series/Studex. Has anyone else seen this? Or are you interested enough to do a quick test of your GX7 body? Just clamp it down tight on a tripod and, using a long lens, wiggle the body and see if the aim point moves. I want to hope that my experience is unusual, but with two bodies behaving exactly the same way I am pessimistic. Edit 6/20/15: Sorry I did not make it clear in this thread that I am dealing with vertical (pitch axis) motion -- like you get by moving the end of the lens up and down. Yaw axis motion (left/right movement of the image center point) is not an issue.