I am demoing a sling shot now. WK built me a Sling Shot vest, fit for my body size, and shipped it to me. I will say the the vest is built for me but its adjustable to some degree both waist size and shoulder. Im 5'8" 165lbs and would say that the vest I have can handle about 10-20% variation on my size and weight. I walked and ran with it both eye height and floor height and it was comfortable and easy to control and absolutely took the weight off my arms. I didn't try really high because I was alone and its not possible to take the movi off the dock when your set for high shots. Some adjustments can not be done alone. There was slight walking bounce in the frame as with the EZ Rig but it was my first time and I was walking in a hallway which amplified the bounce due to architecture being so linear and close to the camera. I don't have the video here. Sorry. Ill try and post some. I have used the EZ rig by itself which doesn't really work except for lock off shots. I have use the EZ rig with the Serene which is good set up for many walking applications. I have also used the EZ Rig with the Serene and Puppeteer which all together is the best combo as far as EZ rig is concerned. As everyone knows it is difficult to get eye height unless your subject is 6" shorter than you. Not often. And adding the Puppeteer knocks you down another 4". EZ Rig may come out with a tall version that can solve this issue. I think that is an easy solution but will cost $1-2000 and doesn't actually exist right now. I find the Sling Shot better as an overall system. Its about the same price as an EZ rig and Serene and Puppeteer but far more adjustable and comfortable. One issue with the Sling Shot is that its hard to tilt because all the weight is below the hook up point. The Puppeteer solves that for the EZ Rig but that won't work with the Sling shot. I think this can be solved with a hook up point closer to the nodal point of the rig, kind of at the bottom of the handles rather than the top bar. Not sure if this is possible but Ill talk to WK to figure that out. It is also hard to pan without turning your body because of the dual hook up points where EZ Rig take the center point. Again I think this can be easily solved when needed by taking the two bunggees and grabbing the center handle when this is needed. I have a job which will be a final testing ground before I decide to buy and will report back after that job Tuesday.