They are both great kits.
The Renwal kit is larger, being 1/500. Revell's is 1/530. IMHO, the Revell kit is better detailed but both look good in overall shape.
For accuracy, the answer depends on which Essex you want to build. The most noticeable differences between the ships are the shape of the hurricane bow and the the bridge window configuration as well as the location of the aft, starboard elevator. It's been a while since I had the Renwal kit in hand but if I remember correctly, the Renwal kit has a hurricane bow shape better suited to
Lexington. If you want to build an accurate
Lexington or
Shangri La, go Renwal, otherwise Revell.
I don't remember what the Renwal keel looked like but hopefully someone here with the kit can check for us.
Oriskany has a rather unusual hurricane bow shape, being flat near the top with a distinct "knuckle" in the shape of a shallow "smile". Neither kit's bow is right for
Oriskany out of the box, but with some basic scratch-building skills, either of the kits' bows could be modified. See:
Attachment:
CV-34 oriskany-reef2.jpg [ 37.06 KiB | Viewed 1024 times ]
Revell's classic Iowa class kits still hold a place in my heart. It's good to see them still around.