The difference is that the CD 22 was designed in 1987 as a lightweight fishing boat, carrying a 70hp two stroke (lightweight) motor.
The Cape Cruiser/Venture was designed in 2005 by the son of the original designer, to have a more modern hull form, and to carry modern higher hp, heavier motors.
The Cape Cruiser/Venture hull has more deadrise, rides smoother, has more interior room, more headroom inside, and in the C-Dory version, has a fully lined interior.
To say the Cape Cruiser and the CD 22 are the same is like saying a 2005 Honda is the same as a 1987 Honda. The Cape Cruiser is a more modern design evolution of the C-Dory hull.