re: coilovers... cheaper ones tend to have stiff springs to take most of the loading, because they run crap shocks which couldn't handle it. The old G4 ones justjap sold were like this. The shocks kept failing people, even with the big spring rates, now they clearing them with no warranty.
Drag racing... stiff is good. Dunno how the BC ones go. Is mixed reviews. Seemingly they are a decent cheap option. As far as chinese made products go; again is mixed pending the industry. Some industries refuse to use chinese made components because of QC issues.