It stopped being viable?
Apparently no one told Rich Shay that his deck stopped being awesome...
Anyway, although this is a really basic post, I'd suggest take a look at recent T8 lists if you want help. There's been so much work done on this deck as of late that there is really little left to test. Your build looks pretty much the same as what I've seen, so it's probably good to go. Plats is like one of the things that distinguishes this deck and Duress is amazing. You only need 2 Slaver.
The thing to remember is that Control Slaver is a very difficult deck to play perfectly. It requires a lot of finesse and difficult decision making. It also tends to be counterintuitive sometimes. To beat other control decks, you need to learn this finesse.
