You forget also something (I know you know it, just to clarify) : SS doesn't affect AA, Crit & Det are. In many MMOs, Melee damage is a lot of total damages, don't ignore the det / crit bonuses on them (and should be obvious, while gaining only 0.10 sec with 100 SS) to focus Det / Crit (well there is this hidden DR with crit, but you can't do a det build without crit ... so . Also, Det sinergies very well with Crit). That is two aspects that SS does not offer (at least with the formulas right now ... Obviously if 100 SS would bring us to 1.5 GCD there is no question ... but this isn't the case and the difference is marginal. Plus, you should know that playing with "haste or SS" is directly affected by the 0.5 sec human eyes are stuck with to "realize" things. Crit & Det are "automatic".