Fact: Nearly went TEIN's for $2300 installed (the SW/SS hybrids). Rought. They leak like crazy. Cusco Zero 2's are hard hard hardcore. They are insane. Very $$$ though, out of my budget. Looked at D2's, they are track rated, but I can take the bumpiness so I grabbed those for $1300. G4's are better on your kidneys as they are a softer rate, that is about the only difference. G4's are $1400 from JustJap and are 36-way damper adjustable, pillowball mounted, camber (i'm sure) and ride height adjustable as well obviously. Both G4 and D2 are bloody good value for money.