|Having worked with both several times, i’d go with z1 if you have oem style injectors. And WS if you have any top feed or other injector with a different connector.
The quality on both harnesses are very good and OEM like. Wire lengths correct, proper heat insulation etc.
Both harnesses feature the dash plug disconnect, which most people will appreciate when feeding thru the firewall. Personally i prefer no disconnects and just depinning the connector myself, but i understand not everybody has the patience for that sh!t.
Only WS has the injector subharness. Z1 does not have this feature. I do not find this to be necessary. If WS were to also make the coilpacks on a/the same subharness i’d dig it more.
WS has the option to add on aftermarket injector connectors. Z1 does not.
Z1 is about $50 cheaper than WS.
I installed 2 of z1’s beta harnesses, one new style and one hybrid. Both at this point have about 8k miles/2years and still going strong/working properly. I have also installed 3 of their production harnesses and those also were good with no issues. Z1’s hasnt been around long enough to stand the test of time, however I have no doubts it will hold up just fine.
Ive installed 3 WS harnesses, one of which has about 5 years and a lot of miles on it and is still functioning properly and staying together. Including being removed and swapped to a less crashed chassis ;)
If WS made a PRO series VG-Z32 harness i’d be all over that, for the nicer quality materials used in harness construction. But they dont. So my next time around i’ll likely be building my own with higher scale materials and some trick disconnects :)