Cheap eBay Intakes

Yeah, you get what you pay for- but on a relatively stock or mild build street motor you'd probably not notice a whole bunch of difference. An RPM/AG would probably be overkill in that situation. The knockoffs are what they are- a cheap way to get a 4bbl. on a mild LA or Magnum.
As a side note, Speedmaster hired Edelbrock's former head of engineering this year- maybe SM is planning to kick things up a notch...