LOTS - I had done a thread on the differences months ago with pictures, but even if you pull it up the pictures would not be there now cause its old and I had to make room for more.
Anyway I'll try to do a quick difference with a few references to other pics.
Medium size body
Modified wedge with strong square muzzle
Tall pointed ears set at a 45 degree angle
Coat - ticked (banded like an Aby) with the spots being formed formed the ticking. Spots should be a darker color then the base. Broken necklaces and bracelets on the neck/legs.
Spots on the side will form a bullseye pattern (spots within spots) - its not as dramatic as the classic tabby bullseye pattern tho. Tail should have alternating stripes and spots.
While the Oci does come in non-spotted patterns from the ASH, Aby, & Siamese background, only the spotted patterns are shown. We also have 12 colors:
Tawny, Chocolate, Cinnamon, Blue, Lavender, Fawn....then add the "silver gene" to make Silver, Chocolate-Silver, Cinnamon-Silver, Blue-Silver, Lavender-Silver and Fawn-Silver.
Bengals (the Bengal breeders can clarify)
Larger heads - more rounded with shorter and more rounded ears then an Ocicat. Body larger (Oci's average 9-12 lbs; Bengal males can go to about 16 lbs)
Spotting is random or more horizonal looking. They also come several spotted patterns (pawprint, rosette, solid spots) And Bengals have a Marble pattern (more like a long bullseye) that is shown. They have a few other patterns (mink/pointed type).
The biggest difference between the two is that Bengals were created from using a wild cat (Asian Leopard Cat). The Ocicats are 100% domestic - product of Siamese/Aby and later a little ASH.
Here's the picture/refernces:http://www.acfacat.com/bengal_synopsis.htmhttp://www.acfacat.com/ocicat_synopsis.htm