Adam,
What rear-weight bias?!
Blackfoot,
The weight distribution of a 911 is not as bad as it looks on paper. In fact, because the engine is behind the rear axle, it cleverly acts like a traction control device, and, due to the transfer of weight under hard breaking, the bias from the rear gives 911's superb brake balance.
You hear many stories about the tendency of 911’s to act like a pendulum. In theory, yes, you can perhaps see how it could, but in practice, well, it's apocryphal; even wet conditions fail to expose dire consequences to Porsche's decision to push the engine a little further back than theoretically ideal to accommodate two kiddy seats.
In my humble opinion, and after driving my 911 in the most extreme of conditions, i.e., several club sprint events, one of them damp, I can safely say that the 911 exhibits more mid-engine characteristics than anyone outside of Weissach, and anyone who has never raced a 911 could fully comprehend.
Matt Holcomb