The major difference between the TackForm Steady Clip and the previously reviewed TackForm C-Fit is the way that the two mounting systems hold your phone.
The Steady Clip uses a sort of spring-loaded grip that you open and close by squeezing a pair of levers on the back of the clip. The Steady Clip can hold much larger devices than the C-Fit can, expanding to hold devices up to 4 inches wide. If you're using your Samsung Galaxy Note 2 or are planning to use the upcoming Galaxy Mega to navigate, the Steady Clip is up to the task of holding your handset in place. I tried to cram a Google Nexus 7 in there; it obviously didn't fit.
Because of its design, the Steady Clip can also close its grips completely to hold products that are narrower than the C-Fit's 2.2-inch minimum -- which is great if you're still carrying a Nokia 3310 around.
Because it has levers to open its jaws with, the Steady Clip is easier to get your phone into and out of than the C-Fit (or the mechanically identical Bracketron Mi-T Grip), but it does require two hands to do so.
The trade-off for the Steady Clip's wider range and easier access is that it doesn't seem to hold devices between its rubber grip pads as well as the C-Fit does. I was able to shake my Galaxy Nexus free by holding the mount by its base and shaking vigorously. To be fair, that's more G-force than the average phone will experience when suction-cupped to your car's dashboard or windshield; so as long as you don't run your car into a tree at 45mph or navigate around a racetrack at breakneck speeds, the Steady Clip's grip on your phone is probably strong enough.
Like the rest of the TackForm lineup, the Steady Clip has a suction cup at the base that is made of a tacky, semiadhesive gel that can stick to most solid surfaces in its own right. This stickiness combined with the suction generated by locking the TackForm gel suction cup in place with a lever resulted in a remarkably strong grip on whatever surface I mounted it on. This is a boon for keeping a smartphone secured and stable while driving, but it can also be a tad difficult (though not impossible) to remove between trips.
The tacky material has a tendency to pick up lint and dirt when the mount is stored or transported without a cover, so the Steady Clip is probably best left, semipermanently, in place in your vehicle between trips, rather than being repeatedly placed and removed like a conventional suction cup mount. If the grip does get dirty and lose its stickiness, it can be cleaned with soapy water and a wet cloth. When the cup dries, it will be sticky again.
The tackiness of the suction cup means that it can be attached to leather, leatherette, wood, and that oddly rubberized "soft-touch" dashboard material. I particularly enjoyed the dashboard-mounting option because it allowed me to mount the phone low and near the radio controls, where I could easily reach it to input destinations or change songs while the windshield remained unobstructed.
Like the C-Fit, the Steady Clip has only one point of articulation, at the ball-joint where the gripping claw meets the mounting arm -- unless you count the spring-loaded jaws. This, combined with the sticky, tacky suction cup, can make getting the mount's gripping claw into the perfect position a bit tricky, but not impossible. The claw does have a few degrees of tilt articulation and can be freely rotated, thanks to its ball-joint connection to the mounting arm. The assembly can also be locked in place by tightening a ring on its back panel.
The clip's arms also take up more space than the C-Fit's, so additional care must be taken to avoid obstructions when mounting it on, for example, steeply raked windshields.
On the other hand, with only one joint to worry about and a relatively short arm, the Steady Clip is quite stable, exhibiting none of the shakiness and vibration that longer, more flexible mounts do when its ball-joint is locked into place.
Fortunately, the Steady Clip's mounting arm lacks the wide, glossy plastic cover that covers the suction cup mechanism on the C-Fit. This makes the Steady Clip's tenacious grip much easier to break when it comes time to remove the mount, thanks to the fact that it's easier to get your fingers around the base. Visually, the Steady Clip's base has more in common with Bracketron's Mi-T Grip, which is a good thing.
The TackForm Steady Clip's tacky suction cup and its 0-to-4-inch gripping range make it ideal for owners of very large (or oddly narrow) smartphones who want to dashboard-mount them, but unless you're carrying one of those phones of extreme dimension, you're probably better off taking a look at the TackForm C-Fit or Bracketron Mi-T Grip with their stronger gripping arms and lower-profile designs.