I've "heard" stories about the manifolds causing engine problems but I can't recall once seeing some evidence of anything other than some leaking vacuum fittings. I think the fittings supplied with most of the knockoffs were junk and if they leak, you're certainly going to have idle issues. As for slag, this one's already been cleaned up and smoothed out so I'm not too concerned with that.

I know, a knock off is never going to be quite as good as the brand name; and ideally I would have like to have a Greddy, but I can't justify $900 for a manifold that isn't 900% better than the $100 manifolds as this point in time.

However, for the sake of moving forward, lets just call the manifold a greddy. What gains are there to be had, and what kind of downsides are to be expected. Would the gains outweigh the losses?