Don't get a cartilage piercing with a gun. It's much worse for you than a needle. I found this online that explains why:
"One final note on ear cartilage: Never never never let anyone pierce your cartilage with an ear piercing gun! You are virtually guaranteeing yourself an extended healing time with extra pain and scarring. Guns were not designed for piercing structural tissue, and can cause damage. Furthermore, the studs the guns use are too short to allow for the swelling caused by gun piercing. If the tissue is restricted during swelling, it is prone to more scarring. Using a gun to pierce cartilage opens the door to a whole slew of possible complications. Don't do it"
You can just do a google search and any reputable source will tell you never to pierce cartilage with a gun.
I found the piercings I had done with a needle hurt a lot less, they all hurt about the same when they were healing. I have the cartilage on my right ear done twice, both with gun and it's like a really sharp pinch that throbs for a few hours then pretty much it only hurts if you lie on it (I usually lie on my right side so that was annoying) for about a week or two. You need to make sure you clean it properly as well, but that goes for any piercing. Oh, and for the love of God be careful when brushing your hair!