The problem with my spa turned out to be a faulty spa light circuit and the dealer had an immediate fix. Quality dealer service and spa.
My understanding is that the C series of Caldera Spas are produced as a special item for dealers that wish to carry them. They have a few less items included which reduces the p[rice by about $1,200. For example, there is no 24 hour circulating pump, no external cabinet lights, no light on the waterfall feature, two less jets, and a different control panel due to the cir. pump. Other than that, they look the same and have the same warranty. THEY DO INCLUDE a Monarch Ozonator and the underwater spa light does change colors or can stay at one color. Such a deal!!
My previous Calspa 15 ywears ago never had a 24 hour pump and it didn't seem to make any different.