I know in Vroman's thread about his deck he cites it as the best draw engine in the game. I don't necessarily disagree, however I find it funny that of all the decks that utillize it, IMO Vroman's has the least synergy.
I disagree with this statement. I believe that all three decks you mention have equal synergy with Bazaar; however, they utilize it in different ways.
In Dragon, Bazaar is used primarily to put Dragons (the win condition) and Deep Analysis into the graveyard as well as improving card quality.
The two Baghdad Bob variants utilize Bazaar with the addition of Dark Confidant to, in essence, draw 4 cards and discard 3 each turn.
In addition to Dark Confidant, Vroman's deck utilizes multiple other cards that have synergy with Bazaar, most notably:
4 lavaman (eating the chaff that goes to the graveyard)
4 jotgrunt (removing the drawback of the cheap 4/4, enabling it to remain on the board "longer than its meant to")
1 riftstone portal
1 tomb yawgs (two lands that reduce the drawback of Bazaar itself--i.e. it doesn't produce mana)
Simply looking at numbers, Baghdad Bob variants have more synergy with Bazaar, as they run more cards that have synergy with Bazaar (i.e. 4 Bob, 4 Lavaman, 4 Grunt, 2 land). I think what makes the synergy equal between the two decks (Dragon and Baghdad Bob) is that Dragon's Bazaar-synergistic cards are more potent, as they lead to winning the game as opposed to, in Baghdad Bob, creating incredible card advantage and increasing the probablity of crippling lock/disruptive elements. However, these lock/disruptive elements in Baghdad Bob, when metagamed correctly, can be quite as potent as Dragon's synergistic "win the game cards."
That being said...
Is Bazaar good enough that decks that don't auto-include it should be testing it?
I agree with Mike the Mad on this one. In decks that don't have access to blue and, consequently, its card drawing elements, Bazaar is a card-drawing engine to be considered. Moreover, in decks that have components that allow you to draw an additional card each turn (i.e. Dark Confidant) and graveyard-value cards (i.e. Goyf, Riftstone Portal, Lavaman, Grunt, hell, even Therapy) that allow you to weather the Bazaar's drawbacks, then it should also be considered. However, in decks that cannot create consistent, turn-based card advantage or utilize graveyard-value cards, like Flash for instance, including Bazaar would be nonsynergistic (if thats even a word).
Just some thoughts,
-Matt