I've seen the manifolds at Powerhouse's store in Bakersfield, CA, and at a couple of other stores/shops in that area. They appear to be a pretty good copy of an Edelbrock, with a lot of effort put into their external finish - nice and polished, with no noticeable flaws; you might say "show quality". As to their performance, as I said, think Edelbrock, or perhaps Weiand, or Holley. Without placing them side-by-side for a visual comparison, or testing them on a flow bench or dyno, the question is sort of up in the air. But, as to their appearance? They look nice.