Ya if you take insanity next patch flay becomes powerful. Been playing around with it on prt. A 3 orb DP into 2 mind flays will take 80%+ of someones hp, that's without sw or vt up, no dispelling or anything. Literally cast nothing but DP and flay and it rapez them. But this does have the downside of, if they get out of range, or u get ccd, and cant get off that flay during DP, then you missed ALOT of burst, and wasted a talent essentially. I'm gunna mess with it some more on PTR, I feel like if I got good with it, the new insanity could be very very powerful. It's just a quite different playstyle than that of FDCL.
Like he said mindflay does excellent damage with insanity when you have 2 or3 orbs and that was without extra dots ticking, which will be fine being as we be ranged interrupted, silenced or even stunned. which why I still believe they should buff our dots further and nerf our PVP power slightly to compensate the over all damage increase. That way we can be happy with PVP damage still and still rock PVE charts and hang with the best. Any fight with more then 3 targets its a dps loss to try to keep dotting everything, over dot a couple and mindsear.