I saw this screenshot comparison on Wired which allows me to mention a point which I was not going to mention due to the hassle of taking the screenshots myself. Thanks, Kif!
Using iOS 6, you could quit four apps at once by pressing four fingers on the four red minus signs. This wasn’t a big deal, but could be fun if you had many apps open at the same time and they would zoom past you.
Now iOS 7 multitasking only allows the simultaneous quitting of up to three apps at a time using a three fingered upwards swipe.