Personally i'd steer clear of china made intercoolers though some have mentioned that their quality control has improved vastly...
the china made ones that i have seen in person...pipings are either porous, bad fitment issues, uneven thickness or have tons of burr that would cut ur hand
the top end greddy kits are beautiful and relatively cheaper, HKS ones are also worth mentioning and Blitz.
Intercoolers while seemingly simple do have some research/tech in them. for example, u want maximum cooling which requires excellent contact of the incoming air with the cooling fins yet u dont want a huge pressure drop. So the tech comes in how efficient is the material used for the fins to absorb convectional heat from the turbo-ed air, then it has to conduct the heat to its outer surface and lose the heat to the cool air passing over it via convection. Some companies manage the restrictive portion by having a special fin layout/design.
hope this helps