@lvsca has also released a thread about bounty information before and he's updated the new bounty with his own analysis, so I think one thread will suffice as long as there's an update with every new bounty release.
I agree with you that there is no need to duplicate threads with the same topic, but that topic lists only good quality campaigns while this topic aims to list all the bounties.
There are many other bounties lunched outside the forum. Maybe op can search for them and add them to his list.
And the most important is to the bounty board there are so many choices depending on how we will choose it.
no problem to create an overview list even all the bounties are there in their main board. In the "services" board, all signature campaigns (btc based paiement) are there, and there is a topic listing all of them with the necessary info in the "Services Discussion" sub-board.