I would put the spark arrestor back in for a few reasons:
1) doesn't look like you were searching for every inch on power WOT all day everyday.
2) SA (except stock) have very little performance effects when left in.
3) This is gonna sound preachy........As a community we need to run SA's when required, we go a bad enough rap from tree huggers, a fire would be major ammo for them.
Aaron