Bloodthirst or Mortal Strike? Follow

MS will do more damage for you than BT will. You don't have enough AP, and unless you have fully improved versions of GoA SoE MoW LotP TA BoK and BoM you wont have enough AP for BT to be more dps. (Takes about 2400 AP with your weapon to have BT > MS for DPS).

The only real difference for your specs is if you decided that you didn't want a weapon spec and went full fury instead. (Slam is better DPS for lower geared people usually, than BT or MS, and you can keep it on a cycle, where MS or BT will not always be on cooldown).

weapon specs are nice, but once you get enough gear to not have that as a crutch, imp berserker stance and rampage add way more dps in the long run, and they usually push BT over MS in DPS.

But if you are also aiming at doing raiding, and are sacrificing for the whole, and no one else is doing it already (don't need 2 MS spec warriors in raid), MS/Blood frenzy is an awesome raid buff machine. Spec imp demo shout, imp tclap, and keep blood frenzy on your main targets. Your raids overall DPS will jump. Especially if you have a drood FF and a lock CoR. Imp demo shout + CoR = armor reduction and no AP bonus to the mob. Those all add up to about a 15% increase to all physical damage. Add in 4% from blood frenzy and possibly more from armor penetration. It's GG as long as the rouges don't pull threat, and you don't crit string yourself into an awkward position.