The Enigma Order

mutilate isnt great for lvling, but its perhaps more fun for some people. the spec is insane for pvp, but the thing is that it has flaws when it comes to pve.
for instance: you do crap damage vs mobs that are immune to poisons. you cant solo mobs that are immune to stun. you can barely handle more than 1 mob at the time.

if im to spec back to mutilate, i will go for some more survivability and crowdcontroll.

my build at 70 would be: http://www.wowhead.com/?talent=whe0RxGRizVobZyM0s0h

maybe drop serrated blades, but its kinda awesome for all scenarios.

your build: if you're going mutilate, you should learn to use expose armor. its a great asset when you have this much combo points as you get with mutilate build. with 2/2 imp expose armor it reduces more than 5 sunders (aprox 3100 armor), and with mutilate you can dish out a 5cp expose armor in a matter of seconds.

imo, fleetfooted is one of the greatest talents in the assassination tree, and it should be a must.

i would skip improved sinister strike, because i hardly ever used it when i was mutilate atleast. when you need to throw a frontal melee attack while waiting for gouge CD etc, ghostly strike is a very good option. you wont have it before 63 orso, but its still boosts your survivability quite alot at the same time as it does ok damage.

hope this enlightened you