One good game is not indicative of a trend. He did have a very good game vs Granada, but has had many more poor games. He has not played well this year. It isn't simply about him not initiating counters fast enough. He has also not been making good decisions with the ball and is holding onto the ball too long in both offense and defense, leading to stagnation on offense and dangerous possession loses on defense.
Cesc and him have not generally player well together when they're both playing in the midfield, and again, one game is not indicative of a trend.
We do not need to change our style, we need to simply adapt it, evolve it. In fact, Barca have not played Barca style in a consistent manner for 3 years now. Tiki Taka is not only about ball control, but about fast passing, movement in space with and without the ball, deep cutting runs from the wings and the midfield, and high pressing. Of that, only the game control remains. Barca have lost the fast passing, the movement, the runs, the pressing.
Adding pace does not mean adding Real Madrid stampede type of counter where 4 players just spring running forward and receive service. Adding pace for us means returning to what made Barca dangerous. Fast technical play. You don't need every player to be Usain Bolt to run a fast pace passing attack. You just need players making quick decisions, being mobile, having vision. I'm not saying Barca should run the hectic game Dortmund runs, but the pace does indeed need to be quickened significantly to be able to compete.
Even though I'm not so sure Iniesta is physically faster than Cesc, it's not about actual speed, but game pace. Fabregas just plays faster than Iniesta. Everything he does is direct, quick. Iniesta wants to slow down, dribble, go back, dribble some more. Right now, that's killing the team. Iniesta himself used to play faster before. He has slowed down his game just as the team has slowed down their game.
Just to be clear though, I'm not saying we should get rid of Iniesta. I'm just saying Cesc should be the focus of our midfield now, and he should play with a player in there that complements him better, and of the ones we have, Sergi Roberto is the best complement.