We own at RCB, have never been to Ron Jons but have driven by. Ron Jons is a large resort, with many is not most units not on the beach. The sand on RJ beach is very powdery and sticks to you, it's a very wide beach at low tide, ocean is quite shallow, requiring you to go out quite far for any depth. Water is calmer as it is next to the breakwater separating the beach from the cruise liner channel, Jetty Park is next door and there is lots of fishing from it. That may be of interest. The cruise liners go by, which may be of interest. RJ is at the north end of town with not much but hotels, motels on the main street, A1A.
RCB has a nicer sand, beach is not quite as wide, water gets deeper quicker and the waves are a bit more robust, You can rent beach chairs and unbrellas at the RBC entrance to the beach, you can walk to Cocoa Beach pier with fishing, restaurants, beach volleyball etc, You can also walk to Ron Jons Surf Shop, open 24 hours, Publix is across the street and if you like to walk, the Old Town Cocoa Beach is walkable to the south, but there is also a public beach shuttle bus that runs the length of A1A. RCB is right on the beach and a much smaller resort than RJ. There is tennis, basketball, great gym, movies all day, water aerobics, and a pool that is located on the west side of the building that offers protection from any cold Atlantic wind, allowing sun bathing, pool swimming even on cooler days. Half of the units offer ocean view with the other half ocean front. The units are big, comfortable with nice size balconies.
Hope this helps