I'll disagree with Kev! If it's just a street car then go with the OEM mount! I had to make this choice recently & went with the OEM mount after taking advice from those in the know! Basically you need to consider the benefits of a more rigid gearbox mount?...... which in turn means less play on the drive shaft = increased efficieny in power transmission to the rear wheels etc! BUT it also means greater wear & tear on your gear box! Remember NISMO parts are designed specifically for race applications where things like gearboxes get stripped & re-built a LOT more than your average road car! So I went for the OEM mount! A bit more to outlay but a LOT cheaper than a possible future gearbox re-build!
I bought the nismo mount, cause I'm a cheap skate Have been using it though for the last 2.5 years and had no issues but then my Z isn't a daily anymore.
If a stiffer gearbox mount has any detrimental effect on the life of the gearbox I will be VERY surprised.
I'm using a Nismo mount, it's not as hard as all that and actually softer than the UAS urethane mount I had previously. Rid quality is fine, I can't think of a reason NOT to use the Nismo mount...
It's good to be different! - just wish the guys who had given me this advice would back me up! I haven't fitted mine yet!......maybe I should bend to peer pressure & just swap it for the NISMO one too!