iSkin has long been a staple when it comes to iPhone and iPad accessories. Some of my favorite cases ever made have been the iSkin brand. They've always seemed to stand up to the test of time for me and stayed on my devices a heck of a lot longer than other cases ever did. I recently put iSkin's new exo case through its paces on my iPhone 5s to see if the same held true and came away pretty impressed. iSkin was also generous enough to give away four exo cases to a few lucky readers, so follow along to read more and find out how to enter!The exo case for the iPhone 5 and iPhone 5s by iSkin boasts dual-layer protection that comes in a few different color options to suit your personality. For the more formal occasion, there are standard black and white options. For bolder personalities, there is a pink/purple option as well as a teal/yellow. I received both the black and the teal and yellow. I find both to be very tasteful and well designed.Although the exo case is only one piece, it's actually constructed of two layers of lightweight but durable materials. The first thing I noticed when I pulled the case out of the wrapping was how sturdy it felt despite it being so lightweight. Putting it on my iPhone was easy enough. Just slide your phone in starting at the top and it snaps right into place. When it comes to actually removing your iPhone, it get a little trickier. I found the best way was to push both sides of the case on the bottom. I then just used my other hand to pull my iPhone straight out. Not the easiest case in the world to remove but definitely not the hardest either.When it comes to actually using the case, the first thing you notice is how light the case really is. I was afraid it would add quite a bit of bulk but it really doesn't. I don't know if it's because it's so light that I don't notice it or if it's because the material is slick enough that I don't feel like I have rubber surrounding my iPhone. Oddly enough, I've actually preferred typing with the exo case on my iPhone 5s because the grooves on the back give my fingers a nice place to rest. Basically, my hand doesn't slide around the back of my iPhone when the exo case is on it. The sides also provide a nice slope which is a nice change from the hard metal edges of a bare iPhone.One thing I always worry about with cases is port accessibility and how hard the buttons are to push down. Luckily, buttons depress great in the exo case and you have easy access to all ports. The exo case complete covers the Lightning port so to charge it you'll need to flip the cover out. The only complaint I have is that the port cover is rather stiff and I can't easily plug my iPhone in with only one hand anymore. I've got to use one to hold the port cover back and the other to plug it in. It isn't a huge inconvenience and something that most people will get used to. I'd also guess that over time the port cover will loosen slightly. I use Auvio brand braided cables from Radio Shack that are a little wider than standard Lightning cables and it just fit. While many cables should fit fine, it's something to keep in mind if you use third party cords.The goodGreat lightweight design that stays out of the way but still feels high classDual-layer design creates subtle grooves that keeps your iPhone from sliding out of your handDoesn't collect pocket lint or dust the way some other silicon or rubber cases doFull access to all ports and buttonsDirt and smudges rub off incredibly easilyThe case doesn't seem to show scratches easily or at allThe badThe Lightning dock port cover doesn't allow one-handed plug in since you've got to hold it back in order to plug in which is slightly annoying, but not a deal breaker in my opinionNot a ton of color options to choose from, but enough to suit most people's tastesThe bottom lineI've been using the exo case exclusively on my iPhone 5s for about a week now and I really don't want to take it off. Coming from someone who typically carries their iPhone naked, that says a lot about this case. I feel it provides enough protection that my iPhone would survive moderate to mildly severe drops but it doesn't sacrifice functionality to do it. The exo case slides in and out of pockets (even tighter ones) incredibly easily and doesn't pick up dirt or dust.If you don't need extremely heavy duty protection, the exo case is a perfect in-between that not only feels great in the hand, but looks great too.$34.99 - Buy now for iPhone 5 and iPhone 5s$29.99 - Buy now for iPhone 5ciSkin exo giveaway!iSkin was kind enough to offer up four exo cases for iPhone 5, iPhone 5s, or iPhone 5c. All you've got to do to enter is leave a comment letting us know what exo case you'd want and why. Is your iPhone case about at the end of its days? Have you broken an iPhone in the past due to not using a case? Whatever the reason, be sure to let us know in the comments.Remember, one entry per person only please! We'll announce the winner next week and contact you about claiming your prize!