I have a question.
I have been considering using Shadowdancer for an ED that I frequent for tough content. If you are a pure 20, It seems that you lose less than you would if you had an 18/2 split, plus you would still have evasion and other defensive goodies from SD. You would lose out on int due to twisting in DC boosts instead, also lose spell pen and durations (caster levels). But it seems that for some EE content this would be worth considering, especially if grinding martial PLs.
Anyway, just looking for further insight into this, as I often miss something important when doing comparisons.