The only thing that I've found so far that you gain from getting higher TH rather than higher kill speed, are the NQ and HQ ground kings. Due to the fact that they're level 75 content, they die so fast that you don't need to have extra stats like str, att etc on them.

My personal gear set of choice on them (until TH12 procs) is main THF knife, no off-hand unless a shield (tatami), gear for 26% haste and TH7, no double/triple/quad attack gear since TH only procs on first swing of an attack round (also hence why no off-hand).

I never ws until TH12 procs at which point full DD it (no TH gear anymore). Though Aspid is the only one of the 6 mobs that is likely to have much HP left after TH12 has finally procced.

Most other stuff, it's better to just farm more pops for greater chance of drops, than to draw out the fight trying to proc TH.