Have you ever...Daggers with Killing Spree?

I purposely used clickbait improper grammar in the title to gain your attention.

Well...so now that you're here...

Have you ever tried Combat spec (PvE or PvP) with Heaven's Fall + Lungbreaker (PvE daggers: 1.80 speed & 1.40 speed)?

How much crappier would the damage be (Killing Spree), in real world PvP? I don't care really about PvE, I'm a gankster 4 lyfe.

I hear that you are supposed to have some sort of macro to switch to 2x SLOW 2.6 speed one-handers right before K.Spree and then switch back to whatever maybe faster for poisons etc. Would I be OK with maybe just purchasing ONE slow weapon with emblems? Any recommendations on which weapon to buy?

Shout outs to all female dwarves, yo.

It's just what tooltip says: 5 attacks with each weapon in short amount of time. Some people are saying autoattack continues while in Killing Spree mode, if you click/macro autoattack, and this would be only reason why Heaven's Fall would perform better than 232 2.6 weapon (furious axe for example), as they have similar bottom/top dmg, but Heaven's Fall has better dps, which would count in during autoattacks. I think you are better off just using 251, 2.6 mh weapon, as combat, in first place, as it would also net you more dmg from Sinister Strike.

I used to play this spec for a short while, when i had mediocre pve gear, and my priority was to apply expose armor, disarm if pala/warr/shaman, and if possible stun before Killing Spree. Stun before Killing Spree gives plenty of time to swap weapons to 2 slow ones, and both with instant or wound poison for added dmg, as well as preventing some defensive cds, like... vanish, for example. On wotlk retail, my friend reported that he was disarmed during Killing Spree, and i tried to do this to other rogue on warmane, only to get vaporized. Basically i saw it as entire spec coming down to Killing Spree ability, but i guess you could say same about subtlety and Shadow Dance.

There were moments of joy, like insta-gibbing wf retri who had gone out of his way, just to catch me, or brutalising high warlord feral who opened on me, and did those all too cocky A>D>A>D moves, then watching them not releasing corpse, probably scrolling combat log for clues of "What the hell". But there were also moments of uncontrollable jumps all over the place. Once my Killing Spree started jumping on totems, i was done, never to come back to it. As i became more experienced i really felt like subtlety is way to go, but you don't know till you try, maybe you will love combat. Best way would be to have both specs, and set of weapons, to swap them depending on what are you fighting in open world.
Protip* you can use premeditation on target, and then respec to combat, within 20 seconds. Points will stay "forever", and you can get full Kidney Shot with just one Sinister Strike, after Cheap Shot. I used this to start off with 5cp Slice&Dice on bosses (Premed can be done multiple times).