We went hands-on with the RooCASE Skinny Slimm, the Glacier Tough, the Gelledge, and the VersaTough. Prices below are Amazon prices, which are somewhat cheaper than the price points listed by RooCASE.
Of the four cases, the Skinny Slimm is RooCASE's answer to a minimalistic case, leaving the thin design of the two devices largely intact while offering protection. The Skinny Slimm protects the rear camera of the iPhone, but doesn't have a lip around the front to protect the screen when facedown on a surface like a table.
The Skinny Slimm is available on Amazon for the iPhone 6 and the iPhone 6 Plus at prices that start at $7.98. There are a range of different color options available.
The three other RooCASE options offer full protection for the iPhone, with varying amounts of bulk. The Glacier Tough case offers complete iPhone protection with a built-in screen protector and it has a clear back so you can still see your iPhone. It's not too thick, but it leaves ports open except for the Lightning port, so it's not resistant to dust and water. The Glacier Tough case is available for the iPhone 6 Plus and the iPhone 6 in a range of colors from Amazon.com. It's priced at $18.98.
RooCASE's VersaTough is another full case that offers a bit more protection than the Glacier Tough. It doesn't have a clear backing and it feels a bit bigger, but it has a solid design with a TPU backing and a built-in screen protector. It also leaves ports open, with the exception of the Lightning port, but volume and power buttons are covered. The VersaTough case is available for the iPhone 6 Plus and the iPhone 6 from Amazon for $17.98
We also took a look at the Gelledge case for the iPhone 6 and 6 Plus, another full-protection offering, but we were unimpressed with how difficult it was to get on to an iPhone, the unresponsiveness of the screen due to the built-in screen protector, and the difficulty of pressing the volume and power buttons. For that reason, we recommend choosing one of RooCASE's other options over the Gelledge.