I think most of the good stories have been told on another thread.
I played my metagame-breaking "36 Bears" in the 128-man "Win a Piece of Power 9" tournament at Worlds. There was an additional piece of Power 9 for the highest finishing unpowered deck so naturally I was expecting to kill two birds with one stone.
I didn't have enough bears to fill out my deck/sideboard due to missing 2 Forest Bear so I added 1 Underground Sea and 1 Lion's Eye Diamond to fill out the deck.
The power of the metagame choice was already apparent. My opponent had used two turns and three cards to do absolutely nothing! I beat him to 11 but he stabilized and came back to win.
He made a comment about trying to do Chalice for 2 in the next game so I sided out as many 2-cost bears as I could and sided in 3 and 4-cost bears. I also brought in Lion's Eye Diamond.
I got stuck on three lands with lots of expensive bears in hand and a Bearscape on board. So I used the Lion's Eye Diamond and lands to generate 6 mana and dump my 5 card hand, making 3 instant speed bears. There's always options with this deck.
Unfortunately, despite getting 6 bears onto the battlefield at once and beating him to 8 I was unable to take this one down. I had given hints of what the deck could do, though, and I still expected to win out and make Top 4.
My powered up second round opponent opened on the play with Mox Jet, Duress seeing a hand of Ashcoat Bear, Grizzly Bears, Bear Cub, Forest, Forest, Forest, Forest. This deck is basically invulnerable to Duress! He Duressed again later in the same game and again whiffed.
In game 2 I sided in Underground Sea and manage to play it as my first land, causing my opponent to say: "zis is ze same deck???" Always keep them guessing.
Later on in the same match I flashed in Ashcoat Bear to double block Tarmogoyf and he was forced to Qasali Pridemage his own Mox Pearl to keep it alive.
This same opponent double-blocked Golden Bear with Dark Confidant and Gaddock Teeg allowing the two-for-one. Sadly, despite getting him to 6 he topdecked like a master when all I was seeing were Forests and Bears and he managed to take the match.
I was still expecting to win my remaining games and at least win the unpowered prize.
In round 3 I managed get an opponent to take more than 20 damage, and only his Zuran Orb-Crucible of Worlds lock was able to keep me from victory. At one stage he was canny enough to block Balduvian Bears with Hypnotic Specter, a very strong play as the Bears can literally do 2 damage a turn.
Zuran Orb-Crucible of Worlds is devastating against the deck as it gains 2 life a turn. If I were to play against this deck again I would probably want to include Primal Command or Chord of Calling to tutor for Spectral Bears, which has 3 power.
Unfortunately in game 2 of this match I mulliganed to zero looking for the right opening hand and died before playing a land. Unbelievable considering the massive consistency of the deck.
So I was out of contention for any of the Power 9. I'm not a man to waste my time when the situation is hopeless plus there was still hope that the deck could stay under the radar and I could use it to win the Vintage World Championship so at that point I packed it in. I think that if I had managed to get hold of the other two Forest Bear it would have been a very different story.
I can provide sideboarding notes for most of the major matchups if people are interested.
You can see my opponent Duressing me for nothing off the Mox Jet plus a short "deck tech" on this video by the renowned transvestite film maker Kieran Symington: