Gunslinger, an almost essential ability. Speeds up the release of your QB to allow you to get the ball out faster. I love this about Gunslinger, there are plenty of throws that I wouldn't make without it. But there are plenty of throws I can't make with it.

I just lost a game vs. a very bad opponent due to this. It also doesn't help that I'm partially blind (I threw a very dumb pick that led to his game winning drive) and my RB has butter for hands (Got popped on Conservative and he still fumbled, he wasn't tired).  But this game could have been won even with those events. My opponent scored with 22 seconds left on the clock and he kicked the ball into the end zone giving me it at the 30. I come out in my normal formation to try to mount a game-winning drive with 22 and 3 timeouts. My opponent happened to come out in prevent. I know how to bomb prevent defense but I don't audible to the formation to do it. I just run a play and throw it 60 yards downfield to Kordell Stewart who is covered by 4 people. Some how it isn't picked off and it hits the ground, incomplete. I come out in Spead Dbl Flex to bomb his prevent defense (Comeback both outside receivers and post both inside receivers). I snap it and watch were his user goes, he goes to cover the post going to the right sideline so I throw it to the open one running toward the left sideline. It is completed and I am pushed out of bounds at the 12 with 2 seconds left in the 4th quarter. My 2 timeouts are useless now. I know what play I want to call out of Y Off Trips Nasty, streak the solo WR and running back, post my TE, drag the Slot WR, and speed out my outside trips WR. I stem the speed out to the end zone and know that is where I want to go even though I had already thrown a pick on the route earlier. I snap it the slot CB is backing up, Deion starts to cut and I see he will be open so I throw it. It was an overthrow due to Gunslinger and I lose. I was pissed and out of anger I put a lot of time and energy to voice my hatred to the Madden Community. Just for people to probably say: "I aint reading all that." 

Rant over.

TL:DR - Gunslinger is great for getting the ball out fast but sometimes it can lose you games you should have won.