The DracoDesign DRACO IV is an absolutely stunning aluminum bumper for the iPhone 4 and iPhone 4S. I tested a limited edition Jewel Beatle on both the iPhone 4S and iPhone 4 for a couple weeks and came away impressed.
It does take a little bit of work to get the DRACO IV installed. It comes in two solid pieces. You need to properly place all the button caps into the proper cutouts and angle the larger of the two pieces so they don't fall out while you slide your iPhone into place. (Yes, it took me a couple of tries!) You can then slide on the other piece and secure it into place with two screws. Of course, that also means if you want to take it off you need to remove the screws, so it's not as convenient as a slide on case if that's important to you. But oh, the look!
The Jewel Beatle has an opalescent finish that alternates from blue to green to purple. It looks terrific. It also has nicely designed curves and angles that make it easier to grip and hold onto.
All the ports are accessible and widely cut, and fit Apple and most 3rd party dock and 3.5mm cables well. I did have a problem with a few extra thick cables, including a car charger and the POP phone receiver. So while you shouldn't have any trouble, do check your accessories if they tend towards the large size.
With aluminum bumpers there are always questions about what, if any, effect they may have on reception. In two weeks of use on two devices, iPhone 4S and iPhone 4, I did notice a drop of about 1 bar on average, on a few occasions, 2 bars. That's compared to other iPhones on the same network at the same time and place. It never caused any dropped calls or loss of data, but if you live or spend time in an area of really poor reception, it's something to keep in mind.
Overall, the DracoDesign DRACO IV is one of the most gorgeous cases I've used on my iPhone. It has a beautiful, sculpted look and the finish of the Jewel Beatle in particular is just fantastic.
Source: DracoDesign USA