The Proaim Sway Pro Portable Slider is a substantial and solid piece of equipment. It feels very well made. It allows for smooth slides and is especially good for pushing in to a subject because there are no rails to get in the way. This means that we can push in with a wide lens, even 16mm, and still get a clear shot. As some other reviewers have pointed out there is a bit of resistance at full extension but I found that if you hold the knob underneath and help it along with a slight twist you can get almost the full amount of extension. Be aware you will need a decent tripod to hold the Pro version, it does add quite a bit of weight. On a portable tripod I would not trust it to be stable at full extension, but with the useful locking feature it holds fine in the middle. Also it is a lot more useful with a ball head on top, especially one that allows a bit of panning. I would like to try it with a full fluid head. The unit screws on to a tripod with the ball head removed, so that works well, apart from having to physically more the entire tripod to change angle.
Proaim Sway Pro Camera Slider (SL-051-01)