I agree that CLD is a great little airport and certainly the closest to Dana Point. However, the only commercial flights I know of into CLD are UA Express from LAX. That would mean an extra flight plus connection time at LAX - probably adding about 2 hours to flying time. Even though the drive from CLD is probably only about 30-40 minutes, the total time including the connection is likely to be longer.
It may be worth it to reduce the hassle of the longer drive, but I think that would be a personal choice. Also, the OP didn't indicate what the original departure point would be, why SNA is not an option, and whether a UA Express connection from LAX would work.