Pow!

You will believe a minion can fly... sideways, at high speed, into a wall.

Energy Blast/Energy Manipulation is my favourite powerset combination in all of City of Heroes.  There are plenty of other sets I like for one reason or another - how they look, how they sound, how they fit a character concept, and of course how they play - but there's none that quite equal Energy/Energy.

Welcome to Knockback City.  Population: EVERYONE.

Along with pure damage every Blaster powerset has a secondary effect - endurance drain for Electric, slows for Ice, even more damage for Fire...  For Energy it's knockback, with almost every attack having a chance to knock the target off their feet and halfway across the room.  Played well Energy/Energy is an incredibly powerful set, with the best soft control in the game.  It's not overpowered - most abilities are single-target and only a couple have 100% chance to knockback on every hit - but one-on-one versus a boss or elite boss I can pinball them all over the map with ridiculous ease and they'll hardly get an attack off while I'm doing so.

It's a very active set.  Positioning is everything and I spend more time on this character thinking about not only where I am but where my enemies are than I do on any other character.  A mob with its back to a wall will be back up and at me faster than one with nothing behind him but open space, and as knockback only has limited effect when a target is in the middle of certain animations I have to watch what they're doing and time my attacks accordingly.  This is why I don't like fighting the Snakes on this character - they get back up much more quickly than other opponents and their body language is harder to read.

Knockback is undoubtedly the most maligned secondary effect in the game, and it's not unusual to see calls in the Homecoming forums (as in the original CoH forums) for it to be replaced with knockdown.  It's unlikely the devs will ever act on these suggestions, but that doesn't stop people from asking.

The core complaint appears to be that bouncing mobs around the room interferes with the herd them up and AoE them down playstyle popular in AE farms.  Having discussed my dislike of Architect Entertainment before I'll only reiterate that these days I don't care what other players do with it, unless it impacts my experience of the game.  Any change to knockback would do exactly that because - and I can't stress this enough - knockback and knockdown are not the same thing.

Knockdown puts an enemy on the ground, but as soon as that enemy stands up he is exactly where he was before he was hit, and that's often right beside me in melee range.  As a Blaster I have a couple of melee attacks, but the main point of these is still to knock my enemies away from me.  If I knock an opponent across the map then I have more time to follow up with ranged attacks, or turn my attention to another more immediate threat.

Knockback takes a foe out of the fight for several seconds longer than knockdown - especially if I can take advantage of my surroundings and throw them off a balcony (or a rooftop) - and since most enemies are at their most dangerous close up there's also a good chance that when they do stand up they'll waste time firing off a weaker ranged attack before charging in again.  By the time they do get back into melee range my knockback attacks have recharged... and off they go again.

I can see maybe the validity of the argument for replacing knockback with knockdown in those melee sets which currently have one power that does knockback, but Blasters are a ranged class*, and Energy/Energy in particular is built around the control and distance that knockback provides.  Changing it to knockdown would make these sets unplayable.

*There are builds that specialise in melee - popularly known as Blappers - but this only works at high levels and with heavy use of IOs.

Aside from all this though it's just fun to see enemies ragdolling through the air.  There's no other effect in the game that so accurately captures the kinetic action of classic superhero comic books, and that alone is reason enough to love knockback.