I love Destructive Touch at lower levels. However, keep a couple of things in mind:

1. It does not work on Bosses, just the Adds (usually)
2. Don't use the skill on a mob that is engaged with another player, you just reduce the DPS for the whole fight. This is more a courtesy thing than anything else.
3. Knock back effects are muted after the first one for 5 seconds, so it's just another attack if you spam it.
4. Since the knock back effect is muted for 5 seconds or so after you use it the first time, take care when selecting the morph. The extra distance one, Destructive Reach, may not be the best Morph anymore. I used to giggle hitting a Mob a couple of time to knock them clean off a cliff or walkway. So, read the Morph choices carefully before deciding what to go with. Although, it is nice to keep the mobs farther away, so it may still be best for you. Your playstyle will decide.