I don't know what people's issues are with Z fever, but again, Martin Struk is NOT Z Fever.
Google RSenthalpy. He does his own work and specializes in Nissans. Whatever horror stories there are about Z Fever, I would be absolutely astounded if Martin was involved.
I've known the guy for about a DECADE, and I can attest to his knowledge and skill in tuning and engine building (as can many, many folk here and abroad). Also, he tuned my VVEL when hardly anyone knew what they were doing with that and we made excellent power gains -- search for my Proven Power Dyno Thread.
Mention me or don't if you contact him -- I don't get kick backs on this. But I do a TON of testing and tuning, know virtually all of the tuners in Tampa either personally or indirectly, and I'd be astounded to find one of them who wouldn't recommend Martin (whether or not they were fans of Z Fever -- my direct dealings with the shop as an entity is more limited, but certainly positive).
As when I post tons and tons of info, dynos, etc, I'm just calling attention to this for the geeky love of data and sharing useful info for folks on tuning, so... whoever you go with, good luck
FWIW: For anyone in the area with a Nissan, I'd say go with Martin + Proven Power's dyno and techs as the preferred option If you are leery of Z fever (again, I've had no issues), or if you go to Z Fever, hang out so you are sure only Martin touches your car, use their dyno and you will be fine
