I'm sorry, Stew, but I've been searching for a while now and found lots of interesting information, but not the answers to the questions I posted. It is not clear in all the threads I looked at whether or not there would be any gains by re-mapping a standard engine with no significant mods (except the popcharger). All of the threads seemed to concern people who had a lot of mods on their cars first. Also, though I seem to remember a thread which suggested something about the re-map removing the JDM limiter, I can't find it at all now.
Here you go Jim:
http://www.350z-uk.com/forum/viewtopic.php?f=114&t=27916
this was simply in the Abbey motorsport section. Theres also a thread called uprev for dummies where a forum member has had his done recently along with all the questions you asked, answered.
But yes you will feel a difference as it opens throttle 100% and also smooths out the torque curve. You wont get much in terms of numbers but the overall driveability will be MUCH better.
Your JDM limiter can be removed also.
For someone who asked about the EPR Throttle controller, this does not give you 100% throttle, it merely sends a signal to the ECU to tell it that the throttle is further down than it actually is thus making it feel more responsive.
Hope this helps guys, im not an expert but have read enough on here to know that the Uprev is a great modification to purchase, from everyones reviews its a no brainer if you have the cash ready.