I had it when I lived in California, and I loved it -- and miss it.
There are drawbacks. Appointments for routine care may take a little longer. You are limited in the facilities you can use (at least for non-emergencies). The care, in general, seemed a little more hurried and impersonal than it can be elsewhere.
But these pale in comparison to what I liked about Kaiser. First, no claim forms, no pay up front and wait to be reimbursed, none of it. Since we moved out of CA and lost the Kaiser plan, this has sometimes been a hassle. Second, if a Kaiser doctor feels something is medically necessary, it's covered. No preauthorizations from insurance bureaucrats counting beans rather than treating patients. My wife had maxillofacial surgery in 2000 -- often not covered and something many insurance bureaucracies would fight -- but she saw the Kaiser maxillofacial surgeon who looked at X-rays and said it was necessary (it was something like a $20,000 procedure). And that's all it took -- he says it's necessary, it's covered.
I'd jump at the chance to take it again if they were in TX and there were facilities reasonably close by. Having said all that, I haven't had Kaiser since 2003, so I don't know if they've declined since then.
"Hey, for every ten dollars, that's another hour that I have to be in the work place. That's an hour of my life. And my life is a very finite thing. I have only 'x' number of hours left before I'm dead. So how do I want to use these hours of my life? Do I want to use them just spending it on more crap and more stuff, or do I want to start getting a handle on it and using my life more intelligently?" -- Joe Dominguez (1938 - 1997)