We've discussed this kind of thing many times over the years, and we have always fallen on the side of fewer forums.
We are a general discussion site. One of our charms is that we allow quite a bit of leeway in discussion, especially when they are on more general topics, like what is the best rimfire rifle.
Once you start increasingly segregating discussion, you lose that character.
We have a search function that works fairly well. Google search is even more powerful for searching for particular topics.
Our model has worked well for us for 15 years, and I don't think it needs to be altered.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.