Ranked in these QuestionsQuestion Ranking
Pro Secure grip
No springs here, either side of the width of the phone have large screws that clamp the phone securely.
Pro The base plate is Arca-Swiss Quick Release System compliant
Failing that the standard 1/4-20 thread can be used.
Pro Easily swivel from landscape orientation to portrait
This is basically a ball mount, but the ball is at a 90-degree angle to the conventional position, so the clamp is spinning in in the vetical plane instead of the traditional horizontal plane. This mount allows some tilt as well.
Con Does not grip phones with cases well.
The depth of the locking arms isn't enough to hold an iPhone 6s with a relatively slim battery pack case on.
Con Sizing flexibility is limited
This model here is for small phones, it can only accommodate phones between 2.3 and 2.8" (58-73mm). So depending on the size of your phones, if you wanted one mount for both small and large phones this probably won't do it. There is a larger version of this product, the MePhoto Sidekick 360+ that can accommodate 2.99 and 3.58" (76-91mm).
The silver lining of this con is that there is less screwing and this makes for a more secure and stable grip on the phone.
Con No attachment points or threads for additional accessories
This mount is meant to only hold the phone and that's it.
Con Needs a tripod
Not stable enough to support phone on it's own, it needs a tripod or something of weight to keep it stable.