I hope that you are figuring out that your chosen model comparison is a lot farther apart than even "apples to oranges".
These two designs each have their good and bad points for cruising and day sailing. They arrive from different planets, design-wise, though.
The J is an heir to the MORC type of hull and the big C&C traces its design heritage to the IOR. You might want to read up on both rules and their good and
Both are "fast"... and I would love to drive the big J Boat off the wind in a 20 kt breeze.
I have watched a C&C 35-3 round up repeatedly in a breeze with the chute up.
OTOH, the C&C will likely prefer going to weather and be better at it.
(Beware of all generalizations, though, even mine...)
Choices and options. Both are well built. Both are old enough to have major issues if not maintained well. Have all the hull coring below the waterline surveyed carefully
. After all these decades, the integrity of the deck coring will depend on how recently all (!) fittings were rebedded.