I may have played Hi Val, but that's neither here nor there.
As with most of your decks, Steve, your Meandeck Gifts list is very focused, and very very good at doing one thing. It is, I won't deny, faster than Brassman's lists in many ways. However, this narrow focus comes with a price. Tormod's Crypt is very difficult for your build in particular to recover from. I know, I know, you _can_ still win once Crypt hits the board. But it isn't nearly as easy as winning before Crypt hits. That one card added to Control Slaver's maindeck really changes the matchup quite a bit..
Let me add this, on the matter of threats to Control Slaver:
Choke and Null Rod both serve to, with a single card, shut down the mana base of Control Slaver to no small degree. Sure, neither card guarantees a win, and neither card alone will end the game. However, both cards serve to slow down Control Slaver quite a bit, because they hit the deck's mana base. If this tempo boost can be backed up by threats, Control Slaver might lose before it can recover.
On the matter of Bob. He is not unlike Library of Alexandria. If not removed, Bob will win the long game. This puts Control Slaver in a position where it must do one of two things: either remove the threat, or go off soon. The former may nor may not be even possible depending on the build. The later is oftentimes the best option, and Bob won't matter if the Control Slaver player goes off soon. However, Control Slaver prefers not to be put in a position where it is forced to become a combo deck before it is ready. Even attempting to "race" Bob with draw is an uncertain strategy, since you are tying up your mana to do what the opponent is doing for free. So, in short, Bob alone won't beat CS, but it can put CS in an uncomfortable possition. Unlike Choke and Null Rod, however, Bob doesn't prevent the CS player's deck from working.
1. Duress
2. Red Elemental Blast / Pyroblast
3. Accumulated Knowledge x4 in the maindeck.
4. Gorilla Shaman
5. Xantid Swarm
Duress/REB: Sure, these cards are fine against Control Slaver. I board them in. They don't "beat" Control Slaver, however. They can help a control deck better executing its plan of shutting down Control Slaver's spells, which is a fine way to stop Control Slaver. Unlike Choke or Null Rod, which single-handedly hurt Control Slaver's development, these cards simply trade for one spell.
Xantid Swarm: This guy can be annoying. He creates a window for a combo player to go off, and makes future counters drawn less worthwhile. Given a proper board plan with Crypts, Chalices, and Duresses, however, his impact can be diminished. Still, quite a fine card against Control Slaver.
AK: I'm not sure there is any good deck that's playing this card right now. Control Slaver was designed to beat up on Tog, which itsself ran this engine. I'm not quite sure where Brian's fear of this clunky engine comes from.
Gorilla Shaman: I keep hearing people say he's amazing against Control Slaver. And he is. Unless, of course the Control Slaver player isn't terrible. I've had this little monkey played against me more times than I can count, and I can count on one hand the number of games he's actually mattered. Control Slaver can hold back its artifacts until they're needed, and the Monkey doesn't stop Library, Tinker (play artifact and sacrifice before passing priority), or Yawgmoth's Will -- and these cards end the Control Slaver mirror match more than anything else. So, Mox Monkey doesn't beat Control Slaver, but instead changes how the opponent needs to play. Your red mana is likely better spent REB'ing a Thirst.