Thanks for your kind reply Mavanas i will try to dive more deeply into the HaT mechanics to improve my understanding of it. You may allow a few further questions.
Am i right to assume that HaT is foremost a viable spec in 25 instances cause in 10 man raids the chance is pretty high that you havent the appropriate setup to beat mutilate/combat?
If the answer is no would you recommend Webbed Death and Hailstorm for a HaT Build as the weapon choice?
On live fast/fast seem to be the soulution to prefer so i could give it a try tonight.
Am i right to conclude that esspecially on setups where the average critraid of each raidmember isn`t all to good for HaT you are better off with spaming evisverate instad of rupture + eviscerate?
As for my gear u may want to take a look at it to recommend geming otherwise or playing around with other stats if its neccesary for HaT:
The World of Warcraft Armory