Well, for me, I prefer to play more with bulky offense / balance teams. Bulky offense is truly wonderful as it can take a hit and dish out as well. However, I don't use Pokemon that are classified as "bulky attackers"; rather, I EV my Pokemon more towards their defense. I always maximize Hp on my Choice Band Tyranitar, and I use the less popular Bulky Gyarados and Salamence Dragon Dancer sets as opposed to the more offensively oriented counterparts. The main problem with using the 4 Hp / 252 (attaking stat) / 252 Spe spread is that, in today's metagame, everything hits like a truck. Another reason is that priority is running around everywhere you look. Bullet Punches fuck up a Salamence sweep horribly, as well as ensuring Azelf and Weavile see no action (non-lead Azelf, anyway). Extremespeeds are running rampant from the ever common Lucario, and while less common that other moves, there are still a fair share of Ice Shards.
Balance is a playstyle that some may see as inferior, though I don't know why; I find that having a healthy mix of supporters and sweepers in a team gives you the ability to not only aid the teams sweepers with greater ease, but check a larger portion of the metagame. For instance: I am currently laddering with a team on my alt (its hovering around #39 right now on the leaderboard) that runs both a Blissey and a Milotic, as well as a Dragon Dance Salamence and an Agility Metagross. Some may call it foolish, but I see it as smart. By using Blissey (or a physically defensive mon such as Skarmory or Hippowdon), you essentially check 1 / 2 of the metagame. While balanced teams are much more common in UU, in my opinion they work just as well in OU.
As for heavy offense, I don't see what the big deal is. A dual screen Azelf / other Pokemon lead is easily shut down by any Taunt user, any Tyranitar, or really any powerful attacker. Its another reason why my leads are rarely my Stealth Rock set-upper Pokemon. Heavy offense is predictible from turn one, when the lead lays the first screen. Once I see that, I just run to my Gliscor / Infernape / other powerful stallbreaker-wallbreaker and fuck the whole strategy. Its extremely boring and jejune and you can see whats coming easily. It also takes no skill to play (the exception being players such as Stath).
Just my two cents.