The whole thing being they don't have to die. Fights can be done short without anyone dieing - Gaara vs. Deidara, for instance, ended up with an unconcious Gaara. The Naruto and Kakshi vs. Deidara will probably end with Deidara getting away with or without Gaara and Naruto glaring at the sky.

Same applies here. Sasori doesn't need to die for the fight to end, he can get away with as much ease. There are hundreds of ways to make Sasori leave the fight - for instance, secret ultra-OMG-important call from the Akatsuki leader (or whatever they have instead) calling him because they need to talk.
Or he runs out of puppets and decides to leave. He gets tired. He starts running low on chakra. He runs out of posions. Sakura crushes his puppet arms to death!!!1111.

Of course we'd be pissed if they killed an Akatsuki member in three chapters, but what I think most people here would like... medium-sized battle, plot development, short battle against the same guy, plot development, long battle, the Akatsuki guy dies.And "long battle" doesn't have to take five months, too, and doesn't have to rely on using bad power-ups every chapter.