I find the Spigen Neo Hybrid a gorgeous very tempting case. Here's my take on it, as compared to my much loved Slim Armor model.
The Neo Hybrid appears to have a flat back. After owning iPhones 4, 4S & 5, I can convey that they're flat backs makes them very slippery to hold and a bit uncomfortable. Built for style and a very sleek profile, I doubt the Neo Hybrid is as protective as the Slim Armor.
Ideally a slightly convex back makes a smartphone very comfortable and secure to hold. In addition if you look at the Slim Armor in Red, White or Blue on their site, it's easy to notice the Black Rubber (TPU) ends. These are cleverly designed to absorb impact should the phone be dropped. The TPU inner liner also serves as the "lip" that surrounds the entire perimeter of the front, thereby protecting the phone when placed face down on a desk or table as I do when at lunch etc.
Finally, Spigen's precise, very high quality manufacturing makes the two piece Slim Armor appear as a single one piece case once installed. I've had nothing but a secure comfortable and pleasant experience from the Slim Armor cases I have.
Hopefully I've answered your concerns