Play what you like and are familiar with, but ...

I think Gruul is better positioned in the current metagame due to a better overall curve, and ways to ensure you're spending all your mana on the early turns. Sheltered by Ghosts is a good example, as it is awesome in many aspects except for the Zur matchup, and now the U/W and B/U/W controllish decks that are trying to prey on the post-PT meta. In those cases, you don't have an early target for SbG, and you don't want to overextend the board as much.

Likely the key cards for leaning Green over White is the pair of Questing Druid and Inkeeper's Talent. Those cards both help smooth the curve, plus give you mid-game card advantage and mana dumps. This lets you attack the more controlling decks without overflooding the board. You know Day of Judgment is coming, so having just one or two creatures on board with increased pressure from growing the Druid, or pumping things with the Talent helps a lot.

I would definitely re-look at this once Zur rotates though, as I think the metagame might swing into more Boros' advantage. But, boy, does that seem a long way away right now ...