I'm not saying the delay of the weapon is irrelevant, but that the ratio is far more important. For example, let's compare two monks. One using the 9/16 epic fist (about the fastest and weakest weapon monks can get; ~14 dps from the bonus) with the Adamantite Club (about the slowest weapon a monk can get; ~9 dps from the bonus). My sperglord calculator (basically a simple multiplication of DA/DW/hit rates etc) thinks:
- Vs Avatar of War: Epic/SoS 52 dps. AC/SoS 50 dps (+4%)
- vs Froglok Krup Knight: Epic/SoS 74 dps. AC/SoS 72.5 dps (+2%)
This is just about the best case for the damage bonus to shine, and it's giving +2%. And the result should be pretty intuitive: the damage bonus just isn't that big. Even in the absolute best case it's only 25% of total damage.