As well, with the newer Slaver decks, they are running counters, which wasn't the case in most older artifact decks. You need to be able to stop them from activating their artifacts (Null Rod), or get rid of their artifacts all together (Oxidize, Rack and Ruin, et cetera).
if they're running counters, what makes you think they won't counter rack and ruin and the like?
to me, energy flux is more like serenity than any of the alternatives you mentioned
once it comes out, it's a major PITA and usually results in the loss of many many permanents