K.C.
I am currently pregnant (due September 19th). I started out with Scripps Mercy in Hillcrest and ended up switiching to Sharp. The reason being is that I really wanted to have my baby at Sharp Mary Birch. Sharp Mary Birch specializes in delivering babies. To me, that was the most important factor in deciding on a medical group.
I have truly enjoyed my experience with Sharp. I have gone on 2 hospital tours and have taken Childbirth Prep and Breastfeeding classes through them as well. They know babies. They know delivery. They know how to make you feel comfortable. Your husband can spend the night. They focus on having your baby "room-in" with you also. They have lactation consultants, breastfeeding support groups, and you even take a class before you are released that gives you more info on taking care of your baby once you get home.
I cannot speak for Kaiser, but I do know that Sharp delivers thousands of babies a year. They are the experts in labor and delivery. Sharp Mary Birch does have a "Baby on the Way" class for people thinking about switching to Sharp. It is free. You can go to their website and sign up for the class. I suggest going. It may help you make a decision.
Good luck!