The Gum Slider for the iPhone 4 is very very similar to the HardCandy Bubble Case. The very notable difference is the exterior material which has more of a plastic feel than that of the rubbery one found with the Bubble Case. 

The design is very nice indeed. The polycarbonate which it’s made out of is reassembly thick. I love the translucency of the red one I have. As I wrote previous this case has a very plasticly feel to it on the outside which I didn’t take to. It is quite grippy however. The inside where the iPhone 4 rests is glossy plastic which doesn't matter because the iPhone is held in the air from the case ever so slightly with the ‘interior rubber guards’ which also help with shock absorbance.

The functionality of the iPhone within the case is good. You have a cut out for everything starting with the camera, volume rockers, sleep and wake button, sleep and wake button, 20 pin dock connector and speakers. The cutouts to all the buttons have a nice smooth sloping effect within the case so when using them your fingers are treated nicely unlike other cases which have very cutty plastic surrounding the buttons.  

To actually get your iPhone 4 in you’ll need to remove the bottom of the case using a sliding mechanism. Once the iPhone 4 is in you reattach the bottom. I found this part of the case to be very well built.

In terms of protection this is going to do fine against scratches and bumps but for big drops it won’t do much to help your iPhone. My case actually has a small crack in it and i’m not 100% sure how it was created. The case does keep your iPhone nicely slim and light which also makes it perfect for pocket use.

Overall this case isn’t my favourite. I found the outside material of the case discomfortable in the hand and in general use had to take it off. The transparency is a nice factor and the functionality is great but the material just lets it down.