My family and I will be spending four days in Anaheim and then traveling to San Diego for three additional days. I'm wondering what the drive is like from Anaheim to San Diego. Is the Pacific Coast Highway a high-speed freeway or should we expect a meandering drive with lots of scenery? Any advise on where to stop along the way and what to expect would be appreciated.

You can drive from Anaheim to San Diego on Interstate 5 in about 1hr 30mins non-stop. You could stop off at Mission San Juan Capistrano, Oceanside Harbor maybe. The coast road (PCH) is not a freeway. It is pretty busy but easier to stop if you see something interesting. The view from the freeway's not bad, you're closer to the ocean on PCH.

PCH will not take you all the way to San Diego because of Camp Pendleton Marine Base. As stated in the previous post the best route from Anaheim is the I-5 freeway. However, an hour and 30 minutes is highly unlikely. Plan on 2-3 hours minimum on I-5 depending on traffic. If you go from Anaheim to the coast, you can take PCH through Newport Beach, Laguna Beach and Dana Point. This will be scenic but slow. Check a map but I think you can also get to Mission San Juan and San Clemente before having to get on I-5 through Pendleton. Then you can get back to PCH in Oceanside for a scenic route to San Diego. Or stay on I-5 all the way. Lots of choices depending on how much time you have to drive.

PCH south of LA is cut up by various and sundry, You're better off taking I 5. There is a high occupancy lane in the area that usually gets the most congested. Capistrano is marginally interesting, but you're better off spending the time in San Diego.

Have done this several times. From Anaheim, go over to Newport Beach on the 55 freeway and take PCH down through Corona del Mar, Laguna Beach, Dana Point, San Clemente. At San Clemente you automatically cut over to the 5 because of Camp Pendleton and that part of the 5 is pretty. PCH is a normal surface street with four lanes, but in typical southern California style parts of it really move out when traffic allows. It will certainly be slower than the freeway, however. Laguna Beach is a prime beach town and good place to stop for lunch or a walk on a pretty beach. Nice little shops there. The mission at San Juan Capistrano is very famous and there's a super Mexican restaurant just across the street. You can stop in Capistrano on either route and if you decide on the 5, it would give you a nice break halfway down to San Diego. I personally would drive PCH and plan to stop along the way, however, if your only objective is to get to San Diego, the above poster is correct in saying just head down on the 5 in the HOV lane.

If you want to see the mission, you should stay on PCH (Dana Point harbor area), until you get to Del Obispo, (turn left), which will take you into the heart of San Juan Capistrano. In the middle of town, turn left on Camino Capistrano. Several of the stop lights have cameras, so do not go through a red light!
PCH will end in San Clemente, and it will swing you right over onto I-5.
PCH has a lot of stop-and-go driving, especially during the summer and ESPECIALLY near Laguna, but it is all the stuff that you see in the movies, etc. and has a lot of typical southern California beach scenery. It you are set on doing this, start out around Huntington Beach.