Butterflys are much of a muchness with boosted cars.
Log manifolds are similar to a plenum in design, and as mentioned i/c piping is shorter and simpler.

im still using the bbm, i still get more low and mid range torque with keeping the bbm operational with boost..
the only thing we changed was the switch over point on acceleration is now at 4000rpm and it switches back at 3950rpm on deceleration..