I LOVE having Kaiser... We had to switch to blue cross for about 6 months when we first moved because my employer didn't offer Kaiser, but as soon as it was an option I switched us back.
1) Great, electronic record keeping. Everything is in there... so when you go to a specialist there is no issue of them not getting your records or something not being on the referal.
2) Referral process is SO easy you don't even notice it happening. No forms. No waiting for HMO approval. No checking for network doctor. If your doctor says "I want you to have this blood work done." That's it. You walk to the lab (down the hall in the same building) and have the lab work done. It's covered. Period. Your doctor says "I'd like you to see a specialist." The doc has the nurse schedule the appointment for you right then!
3) Great advice nurses on call 24/7
4) You DO get a primary car doctor now who is YOUR doctor and you'll always see them, or get called back by them etc (that's a change from several years ago). However, it is really easy to get appointments when you need them because if you don't mind seeing another doctor, they can almost always fit you in with SOMEONE almost immediately.
5) Pharmacy is right there, and if your doctor prescribes it, it's covered. Done.
6) Great groups and classes at most medical centers. Parenting classes, weight management classes, birthing classes, diabetes class, ADHD group, etc.