The Gemini had a bit better power/weight. I think I only ever saw one during my time at Packards but remember it went OK, as well as an Isuzu could go I guess. From memory there was a flares/wheels/suspension package that worked quite well, enabling you to stay on the loud pedal a bit longer in the twisties, hence they felt a bit quicker than a std Gemini. Can't remember if they were 4 or 5 speed though.

Haven't ever seen a CDT commodore in the flesh.