My J30 will try to maintain speed on an incline at its top gear 4th. So the acceleation need to maintain speed is gradual and not abrupt like the RX330.
Also, the RX330 has a tendency to overshoot its set speed, disengage the throttle and cruise back down to speed, and then engage the throttle once set speed is met.
I think that the ECU is the culprit and not CC, and I think that its linked to the other "acceleration", "transsmission lag" problems reported on this and other boards.
BTW, I did have my ECU re-programmed per existing TSIB# TC005-03.
JL