spacebird - the number before the decimal point is the model. Higher is bigger. The number behind the decimal point is the iteration. Higher is more recent. More recent products incorporate all the learned advancements (that can be afforded).
Next up the ladder for you, if you have a larger room or want bigger bass or louder playback might be a CS2.2, 2.3,2.4. The 2.4 is a stellar sweet-spot.
I'm working on a product summery / timeline to help make the product journey clearer.
Welcome.

