Why would anyone want to remove the KB from nova???
Serious though, I would never remove KB from mine. Nova is my favorite power in the game (even though the shorter recharge and no endo drop sort of cheapens it for me a little). Dealing massive damage and "arresting" all the minions and (usually) all the lieutenants as they fly in all directions. All the team now has to do is focus on bosses.
As far as missing the -recov and long recharge, I liked having to tell the team, "nova is up" so they would know I was going in. Aim, Build up, run in, NOVA, eat all my blues, total focus a boss, then start blasting. Now, especially teamed with a kinetics, it almost feels like part of the attack chain, rater than something special.