Steering Over-boosted?
 

My previous car was a 2001 BMW 530, which had fantastic steering feel.

In comparison to my G37 Sport (assume 370z is the same) the steering is too over boosted at speeds below 60 MPH.
In looking at how the variable assist works, it would be very easy to reduce the boost and get more feel.

Am I alone in feeling it is over boosted and has anyone modified the system to reduce power steering boost at all speeds?

I don't feel any overboost, though I'm not sure the steering is the same in the 370 as it is in the G37. My steering feels moderately heavy and is a stark contrasts from any of the G37's i've driven.

Your not alone, coming from a Z33 the light steering feel is one of the few things I dislike in comparison. I haven't seen any modified systems, but definitely would like to if it is possible.

To me, the steering is too sensitive at higher speeds.

After reading the STC section of the FSM, I will scope the power steering solenoid valve and document the duty cycle at different vehicle speeds and engine RPM. Ideally I would like the power steering assist to be much less and CONSTANT.

A lower average voltage at the PSSV (~2 volts) = the reduced assist we experience at 60 mph.

Something like this may be the solution:
AutoSpeed - Modifying Speed-Sensitive Power Steering

Yes it does change at higher speeds, this was specificaly desinged in order to recieve better control on low profile tiers.

If am not mistaken.