The Flood is the same cesspool it has always been, and I say that with affection. Unbanning controversial topics gave the community the ability to actually hold discussions that actually encourage thought. In the almost five years I've been here now, that is the best change I've seen. "OMGZZZ SLenDERZZ MAnzZZ" can give way to philosophical debates where posts stretch pages and people actually feel a sense of worth in what they put forth.
Of course, just because people are given the tools doesn't mean they're going to use them or if they do use them, use them properly. I get that. Not everyone is capable of holding a mature, thoughtful discussion, but the Flood is the same as it has always been (at least in my time here). It's a pile of useless topics that have absolutely no worth or meaning with some real gems strewn through the mess. All the moderation in the world wont change that.
Use the tools Bungie gave us. Self moderate and try and filter out as much of what you don't like. Create your own experience, and let other users enjoy theirs. The Flood forum is the same as it always has been, and pinning the blame on previously banned topics is silly. They opened up new horizons for the forums. If you want to drown out all the threads you don't like, put your focus into creating threads that you see to be quality, as opposed to trying to ban things you don't like. Be a trend setter. Don't fight the tools given to you, utilize them, and I mean that in regards to both the new moderation tools and the new found topic freedoms.