Suppose to increase the air volume in the manifold which will help eliminate turbo lag. Their website list all of the advantages. Using their dyno numbers Boomba shows there is a HP/Tq increase...
Put on a Boomba manifold intake spacer and newly painted engine cover. I am buying the NGK plugs and will install those once they come. I'm a little disappointed that the cover doesn't sit flush anymore, but once I get everything in and put the strut tower back on, it'll grow on me.