I would guess that pintless injectors are the norm since they cost less to manufacture, less prone to corrosion and mechanical failure and the perform better (less mass to move rapidly) because of quicker response time from the ECU signal due to less mass at the metering end. I noticed improved performance when I replaced all 6 OEM old style with the OEM new style in my 92 NA, it is more response to throttle although I also used the 300 Degree fuel rail and there is some performance gaine with that but I am not sure what amount compared to the injectors. I think for the Z32 NA the 300 D rails are more than adaquate for fuel flow requirements of that stock engine and due not offer much performance gain and the majority of the gain is a result of the new style injectors.
