I don't mean to hijack your thread, but I'm in a similar pickle. I swap between destro and aff depending on the fight. I was using 2pc plus 2 WF items, but last night I got my 4pc. Understanding how awesome 4pc is for destro, I was hoping to use the 4pc set for destro and the 2pc/2 WF for aff, but the hit disparity between the two sets is too high and won't work unless I reforge/regem when I swap (ain't nobody got time/gold for that).
I guess this means I need to just fully commit to destro for the time being and go with the 4pc...?