Basically, discussion has concluded that certain weapons should have advantage over other weapons depending on range.
The problem I see with this is that we'll end up with a system where a certain class of weapons is considered "best" and the other classes are ignored.
One way of avoiding this situation is to adopt a "rock paper scissors" model. That is to say, if there are weapons A, B, and C, then A has advantage oevr B, B has advantage over C, and C has advantage over A.
Of course, Planeshift would utilize a more complicated version of this, but the general idea remains.
A real life application would be striking versus grappling versus kicking. If you face a grappler, you want to kick him to keep your distance. If you face a kicker, you want to get in his face and strike him. If you face a striker, you want to grapple him to the ground and get him into a submission.