I like the extra combo effect because it's some nice visual feedback. The closest thing off the top of my head that I can compare it to is how every enemy explodes when they die in Kirby Super Star, so you know they are dead. It just feels good and lets you know for sure you've done it. Also it's nice to not have to be staring at the bar as much and instead glance at it at the corner of your eye.

However, I'd of course be all for an option to turn it off or any visual/audio changes to it.