As has been pointed out, Dr. Boom hero with double Curse treasure is pretty much an auto win. I'm not that great of a player, so it took me a second time to beat the Brawl. Folks need to jump on it before Blizzard decides to make it a little harder.
I wouldn't say it's that much stronger. Stacking the Curse treasure and Randomizing cost of cards combined with picking all big stuff works well for every class.
Beat with each champion... Rogue (theif/trickery) and Shaman (battlecry) were most fun IMO ... But I do have one question.... Given the chances at RNG ... WHY in the world, is the 4th boss Gorr/Garr/Gnar whatever his name was, the hardest part out of the entire TB run... seemed to be the case with each play through, or maybe I just don't know the secret to beating him outside of the obvious, tick each of the 0/5s down so they pop at different times ... don't get togwaggle dice and brawl on turn two.... etc..
Very nice tavern brawl, they were a bit boring lately in my opinion. I went rogue and after my first run and going as quickly as possible I got it in 21 minutes and 48 seconds. I'm not sure how the counter works because you need to think a bit about you card selection and treasures, but under 40 minutes is not really hard :)