Case-mate has released tons of great cases and I have used quite a few of their products in the past. The Hula case is one of them. The Hula case is a bumper style case which is definitely influenced by the Apple Bumper case. Even though it is much like the bumper case, it has it own uniquenesses. Some of those are the cutouts, clear body, rubber quality, and the button covers. The case features a clear body all the way around the case, unlike the bumper case which is not. Also, some of the cut outs are different as well. The headphones cut out has more space then the bumper case, and the vibrate switch has a larger cut out. I feel like you will have more different types of headphones fit into the iPhone 4 with the Hula case on. Also, the vibrate switch is easier to access then the bumper case. Now the rubber material is definitely different as well. Apple Bumper case rubber feels a lot smoother and better.
There are quite a few negatives I have experienced with the Hula. One of them is that the rubber quality is not as good as the Bumper case. I currently have the yellow color and that color is starting to fade away. It is not as bright and some of the dirt stays on the case. Some you can get out and other just stays on it. Also, the rubber is pealing in couple of spots, so it takes it away from the look. It doesn't feel as smooth and nice as the Bumper case. The sleep/wake button is covered by the rubber material, and it is not 100% comfortable to press it. Pressing the sleep/wake and volume buttons is a lot easier on the Bumper then the Hula. Overall, I would say I am still pretty happy with the Hula case. It will only run you $19.99 with free shipping. Also, you will be getting a screen shield for the front and back of your iPhone 4.
Comparing both of the cases, for me it is pretty equal. The Bumper has better rubber material, and button covers. The Hula has a better price, and includes a few extras. Now talking about one being clear and other not, I would put that in the middle. I prefer either and like both equally. So in the end I would still probably choose the Hula case because of the better price, and the extras. Paying $10 for the Bumper case is a bit high and you would still need to get screen shields to protect the front/back of your iPhone 4. In the end I would recommend you to try out the Hula case.