There are quite a few who post on both forums, you and me included, and - in my perspective - both forums are a bit different. I enjoy them both, but in different ways. The prevailing wisdom on P&B is this is largely due to the difference between a single-team forum and a multi-team forum. On P&B you are pretty much forced to interact with supporters of other teams, whether you like it or not. This moderates the behaviour of some posters, and makes others worse, but it definitely changes the overall dynamic.