Some biners are better for certain things. One example might be using an oval carabiner to rack wires. Some prefer racking with other types such as pear or D. Ovals can also be used to make back-up rappel devices and i am sure they are great for many other things. I just don't use them. IMO these are the most useless. Of course, many would disagree. The bent gates are for ease of clipping into. The wire gates are to safeguard against flutter. To demonstrate this, take a regular carabiner and smack it against your hand. You should hear it open. Now take a wire gate biner and do the same thing. Quiet. Gates opening is the number one cause of biner failure. Hence this design. I'm sure others will comment more on what else other carabiners are good for but there is a quick answer for you.
(This post was edited by ChaseLeoncini on Jun 14, 2013, 8:51 AM)