I have to say the JWT is worth the few extra dollars. I installed the JWT kit in my 91TT I just like the injector hold down fitment and the over all quality. As for the other Yes in my eyes the Z1 kit is nothing more than a the Deathworks kit in a Z1 wrapper. The CZP kit is the lowest priced kit and i just did not not have a warm and fuzzy inside when installing it. Granted the Z that revived the new injectors has hot had any problems but I was worried that it would not seat the injectors fully into the rail. Over all yes they all do the job with no issues that i have found however The JWT kit just seams like its manufactured to a higher standard.