The haste effect would only be desirable if DRK's offensive toolkit was nothing but GCD weaponskills...

But because DRK has 2 glorified GCDs that are oGCD and 2 glorified oGCDs on GCD, both of which are basically single target and AoE, and 3 spells that make skill speed not worth getting, terrible MP regain, among other things that aren't related to the topic in this thread, it's no wonder why DRK has become the class everyone wants to like but can't because of design choices that make it not worth recommending to other players...

And no you don't need skill speed for 5th Bloodspiller in Delirium, that myth has been debunked and skill speed is only ever applied for server ticks, the ablitiy will get qued in at 0.5 seconds before the skill/GCD is ready...