I don't think I will use the +/- system if it becomes a feature. For me, personally, I don't feel the need to declare to anyone what I may personally feel.via a + or -. If I do feel strongly about a post, I would so elect to reply, or at least question for clarification. This would give the poster a clearer venue to rebut, and to rebut me for my specific reply. I think it is a bit more difficult to rebut a (-) in any coherent fashion. If I consider a post "rubbish" (and I very seldom do and so far never), I simply would ignore. If post and replies begin to fracture the forums cohesion, there are already remedies in place to deal with it.
I feel very, very comfortable in my abilities to assess, analyze and draw my own conclusions based on contents of the post. So to with the post's replies. A ( + or -) tells me precious little as to why for that particular indicator.. I think I would ignore the + or - much more than the post itself. A post would tend to be far more revealing about our forum members. A (+ or -) is far to easy, very little involvement required. Now after saying this, I must admit that sometimes a post can reveal nothing more than a thumbs up or down, very little substance, no justification other than displeasure. At those times, I simply say, shucks tooooooo bad. Unable to learn anything more than someone is dissatisfied with a particular poster or post.
Now for the situation where I have the need to let people know the post (and in some cases the poster) is poop, troll or otherwise .......nah.........., no need. for a + or- . People will eventually know on their own and will decide how they want to respond .........or not.
Then there is the entertainment value. Someone who is way, way out there in left field, jumping around getting all kinds of attention by being a boob can be somewhat entertaining.......until the entertainment value quickly runs out that is. When that happens, well........, off to another thread. I recognize I have the ability to do just that. I don't need to sit there and become bored. I think we all can sense when this is happening and will deal with it accordingly.
My very, very best to all.,