You really aern't timing your roll dodges to the timer of the weapon damage buff. You are timing them for when you need to roll dodge (dodge snipes etc). In addition to this, the weapon damage boost is very mediocre, and the increased stealth detection radius is 100% useless outside of PvP and really isn't useful inside PvP either.Why is it even less effective? The 5th set buff after dodge lasts longer then the dodge-fatigue.