I agree fully with all of the arguments extolling Pathfinder's Channeling.
But I also like it for another reason. As with most other elements of D&D and Pathfinder, I look to the original mythical or literary source material for how well it models events in the source stories. What is the source for Turning Undead? When people confronting vampires with a cross and forcing them to cower, flee, or turn away, hence "turn undead."
But I've never read a story where any other type of undead was forced to flee because of a cross or other holy symbol, unless the story as based on or clearly influenced by D&D. Crosses never repelled zombies, or mummies, or animated skeletons, or ghosts, or anything else. That is, until fantasy fiction started to become influenced by D&D, at which point Turning Undead started to become a stock power of Cleric type characters. But in the original source materials for D&D, it wasn't anywhere to be found, that I know of. If I'm wrong and there are lots of stories I haven't read where holy men force zombies to flee by presenting crosses, then I apologize.
But with Channeling there isn't anymore undead turning, forcing a vampire away against its will. What Pathfinder gives us is a Cleric presenting his or her holy symbol and causing damage to said vampire (or other intelligent undead), at which point the vampire, being intelligent, might well decide that fleeing is in it's best interest.
Or, even if not causing the vampire to flee, the damage from the channeling would at least causes it to flinch, shy away, and back off as if in pain, which models the behavior I expect from a vampire when presented with a cross much better than causing it to automatically flee in uncontrollable terror, at least in every vampire story I have ever read or seen which isn't based on Dungeons & Dragons.
Therefore I prefer the Channel Energy ability because I think it models the source material of the game much better than Turn Undead ever did. I've never seen a vampire movie where the vampire hunter or priest or exorcist or whatever brandished a cross and caused the vampire to uncontrollably flee in terror, but I've seen MANY where the hero presented a cross and the vampire flinched away from it, holding up its cape as if warding off an attack, acting as if the cross were causing it pain. Which I think the Channel Energy ability models nicely.