Hi everyone, I'm very interested in the two systems named above in helping those long days using a heavily loaded MoVI, or just for some of those slow precise shots. But am not sure which to get, I'm leaning towards the slingshot for its range of motion, but find the price for it a bit surprising as it relies on rubber bands, where I can see some good engineering in the serene for less money. But I haven't seen or used either of the systems and wondered if any of you out there had and what you findings and advice would be. Thanks Mark