Sonic Boom tends to get written off by a lot of Engineers, on the basis that a 30 second cool-down makes it useless. What I have not seen is anyone explore the numbers and actually prove this idea. So I specced Sonic Boom, Wither and Leech all at rank 6 and started doing some solo runs while recording the numbers.

While Sonic Boom only did about 10 more damage per hit than Wither/Leech, I was able to reliably use it within a couple of seconds every time it came off cool-down on a pack of 6 or more trash mobs on Numa1. Wither NEVER ticked for full duration on Numa1, Leech did sometimes but only on the named mobs or the rifle mobs.

On the later Numa levels Wither and Leech were able to tick for full duration more often, but then I frequently ended up with situations where a second cast would not reach full duration. I also had issues with Sonic Boom, with the trash mobs hitting just hard enough that I could not reliably make packs of 6 or more mobs to use it on safely. Playing in a group would probably make Sonic Boom easier to use effectively on levels with tougher trash.

I suspect the efficiency of Sonic Boom VS Wither+Leech comes down to something like this;

- solo trash farming packs, use Sonic Boom
- grouping with people who like to AoE packs, Sonic Boom
- skipping trash to boss farm, use Wither+Leech
- ungeared and/or fighting mostly single mob pulls, GearUp+L2PackPull