Jimmy C.
I've tried so many of the gyms (HIIT focus or otherwise) in the South Bay and I simply do not get a better workout than when I'm at Unlimited. The trainers are all super nice and, almost more importantly, knowledgeable about protecting your body through good form and modifications (for when I'm injured. Added bonus that no two workouts are ever the same which forces me out of getting complacent and keeps me focused.