Decided to just take the risk and get the HyperVoltage MR (Multi Range) unit and glad that I did, noticeably increased pull, and engine runs smother through out the rev range especially from 6.2 to 8.3K.
Easy install, only two wires, 15 min of work. Took a few runs for the ECU to recalibrate from the battery disconnection during install, after that it was all good.
About the same increase in power that I experienced with just the ground wires, not huge but definitely there.
So to answer my own question; I'd say yes.
got it from:http://www.rxecret7.com/hyvopa.html
Yeah, I know it's an RX-7 site but hey they had the cheapest price I could find.
$150 plus $10 shipping.