There are really several differences:
1) Aluminum tube vs plastic tube, aluminum conducts heat better so it's not quite as good, although this has very little effect on a moving airstream inside the tube
2) Cheap filter, but you could resolve this issue by buying another filter. In my experience, even the cheapo filters are decent, better than stock.
3) This is the big one, no heat shield. Installing a cheapo or home made intake that draws hot air from the engine bay WILL decrease power and mpg over the stock CLOSED intake setup.
Keep these things in mind and you can buy and modify a cheapo intake and make it a good one.
Breathing in and out is good enough for me.