VVT-i is a more performance-oriented engine management system than the iDSI. But a better comparison for the VVT-i is the VTEC system. So the two isn't a valid comparison.

And BTW, Toyota ECUs are devoid of any tunable engine governor variables, unless you're working for TRD, TOM'S, etc... On the other hand, there has been plenty aftermarket computer tuning kits for the Honda VTEC-equipped engines.