Supmaynn: Wow... I can't believe you're still shopping around for a gym. I thought that you had already made up your mind on where to train. I've responded to almost all of your other inquiries for information in Orange County. It sounds to me like you need to actually get your ass into the gym and try these places out (by actually training there). Also, you need to figure out what your goals are for training. Fun? Exercise? MMA? Not all gyms are geared towards the same goals. In any event... here's what I know about all of the places that you've listed:
1) OCJJ- This place used to be Gracie Barra America. The owner of the gym (a Rigan Machado student) got into a dispute with the Gracie Barra guys and kicked them out. So overnight it went from being Gracie Barra... into a Rigan Machado affiliate. With his resources, he hired a JKD practioner, James Wilkes to come in and teach some MMA and standup. He also has three black belts there... a Macaco black belt, a Rigan black belt and Rani Yahrya (Rickson Gracie's former student who competed at the ADCC). Nevertheless, the instructors are all legit. They're a relatively new school.
2) OC kickboxing- BJJ is taught by Cleber Luciano (or he sends one of his advanced belts down there to teach). Cleber is a Rickson and Royler Gracie Black belt. He is the real deal. He has one of the largest competitive BJJ teams in Orange County and they do well. His personality rubs people the wrong way and his annual BJJ tournament, Copa Pacifica, is rife with accusations of biased refereeing and administration (favorable brackets for Cleber's students). He has his supporters and his detractors. Nonetheless, he has a solid track record.
OC Kickboxing teaches JKD. Yes, you will learn muay thai here. However, it is integrated into their JKD system along with Savate, Wing Chun Kung Fu, boxing and FMA's. They don't exactly produce fighters here. You probably wont become the next Cro Cop training here but it's not a bad place to train. The instructors are friendly, the chicks are hot, and the facility's good. The place is a bit pricey.
3) OC Muay Thai- The training here is old school Thai. This means hard hard hard. This is a muay thai only gym. Nonetheless, many MMA guys come here for extra work on their standup. If all you want is muay thai, this is as good as it gets in Orange County.
4) Apex JJ- Located in Mission Viejo. The instructor is Chris Brennan's Next Generation Fight Team member Jeremy Williams. I've never been here but I have several friends who have trained with Jeremy and all swear by him. They do a ton of no-gi jiu-jitsu with some muay thai and an occasional wrestling class thrown in. Naturally this gym is more MMA focused. If you want to become a great striker, this is probably not the place. This is a "ground based" school. Nonetheless, you can't go wrong training here.
5) No Limits- I thought you signed up here. In any case, this is where Team Oyama is. Coach Oyama's muay thai credentials are beyond reproach. The BJJ is taught by Luciano Prado (a Joe Moreira black belt). I've tried this place out when it was newly opened. They didn't have many advanced BJJ guys to roll with at the time. I don't know... things may have changed since my last visit. The facilities are nice. The idea of having you prove yourself by being in shape and knowing the basic fundamentals (via taking the cardio class) is a good idea. Or would you rather be thrown into a ring to spar knowing next to nothing? Muay thai isn't taekwondo. You can't just practice the techniques in isolation. What makes muay thai so special is that you actually do live sparring against opponents. A beginner in bad shape and who has no knowledge of the basics is apt to hurt himself sparring. Besides, it becomes a waste of time for all parties involved. They are also on the pricey side but I consider their rates reasonable considering what you're getting.
Bottomline, go try out classes at each of these gyms (they each offer free classes). Your own opinion matters more than anything you'll get off an internet message board. Go with whichever gym you like the best.