The Acase Superleggera PRO is an interesting concept. Instead of one case, why not offer 2 in 1 purchase. The inner layer of the case is made of silicone while the outer layer is hard case polycarbonate that goes over the silicon layer. Slip one over the other and viola! Double protection. This is novel but its actual utility is somewhat fuzzy.
Much more interesting is that the silicon inner layer comes with dust caps (flaps) for the charging port and the headphone jack. To use them, you need to flip open these flaps. If you work in a dusty environment, you will find this very useful as the headphone jack is known to collect dust/lint that affects performance. Btw, watch this youtube video on how to clean your jack if you are having this problem. On the other hand, if you use the headphone jack a lot like I do and drives around with a car charger always handy, this constant need to open and close the flaps gets old fast. Whether this case is suitable for you or not depends on how you use your phone on a daily basis.
The price, however is right for what’s offered. The Acase(TM) iPhone 4 and 4S Superleggera PRO Dual Layer Protection (Black/Black) case (Fits AT&T, Sprint and Verizon iPhone 4 and 4S) is available from Amazon.com in many different color combinations.