I should preface this by saying, your rank is well done. This is purely to point out the difference the talent makes. I firmly believe that playing better will make a much bigger difference than any talent ever could.
Your own rank, 715k dps, 4:37 long
Damage done by Insanity: 8.27M
Damage done by Insanity Mastery: 3.44m
Perfect uptime sacrificed in order to maximize Insanity: (calculated as ticks lost on target)
Ticks gained from proper uptime: 34.4% (167*0.344=57.5 ticks lost)
Ticks gained from proper uptime: 47.8% (138*0.478=65.9 ticks lost)
Ticks gained from proper uptime: 21.7% (177*0.217=38.4 ticks lost)
Ticks gained from proper uptime: 27.5% (140*0.275=38.5 ticks lost)
Ticks gained from proper uptime: 5.7% (191*0.057=10.9 ticks lost)
Ticks gained from proper uptime: 14.2% (160*0.142=22.7 ticks lost)
Your lowest SWP was 25.647k
Your lowest VT was 31.961k
Adding in base boss critical chance and 9.7% amp on crits you get an average tick of:
Total number of ticks lost
Total damage lost:
The reason I used ticks lost as a calculation was so that I could add it up as the worst possible damage per tick, This proves that even doing the worst possible damage per tick, its still better than wasting it for insanity uptime.
Your DK is where I'm getting the perfect uptime from, if he was able to do the mob, so were you, you deliberately choose to not dot it, in order to maximize insanity uptime, It cost you damage, plain and simple.
And most importantly the final tally. The damage bonus from running insanity if you actually do attempt to properly dot everything.
Running insanity gained you half of 11.71m vs no talent in that row at all.
However, lets compare that to what you would have if you had not taken insanity, and instead maximized uptime. You would lose all your insanity damage (11.71m) and you would gain 9.354m in dot damage. However because you were not taking insanity, this opens up the option to take Mind Bender. Taking this would remove the entirety of your Shadow Fiend damage (2.97m) but instead would give you 7.73m of Mind Bender damage. Best yet, all of this is assuming it wouldnt give you any bonus time to cast a filler flay at all, which in all likelyhood it would.
A quick tally shows that replacing your focus on insanity with a focus on dots and using mind bender would give you: 2.404m more than you did.
Making these changes would have put you at 720,093. Just barely behind 6th rank. Almost 5k dps higher than you are currently.