Having changed a lot of things, I did reasonably well with this deck, going 5-2 (officially 4-3, see below) at "Tuesday night magic" against some pretty solid players.
Game 1 (4 colour Sliver Aggro Deck) 2-1 win (really a 2-1 loss)
This game was a 2-1 win to me, but only because in the last game the guy (experienced casual player, but was his first time at a MTG event) forgot to attack for fatal the turn before he lost the game, so I told him he could have it and it was officially recorded as a loss for me. Oh well. The hardest part about facing decks like this one was the sheer volume of creatures that were being pumped out - and especially against cards like Predatory Sliver, my Drown in Sorrow just couldn't deal with it. That being said, in the game that I won, I managed to control the hell out of him and win quite easily
Game 2 (Rakdos Minotaur deck) 1-1 Draw
This game was pretty tough. The guy was quite a good player, and he pulled out a Whip of Erebos early and managed to get himself up to 40-something life in the first game so I scooped. The second game I sideboarded in Dark Betrayal and Erebos, God of the Dead and beat him in quite a drawn out game leaving no time for a third.
Game 3 (Orzhov Constellation Deck) 2-0 win
This game was a bit of a walkover - beat him in a drawn out 1st game, then sideboarded in feast of dreams and dark betrayal and it was too easy from there.