>>6127555CS series was a short lived collector's line of high quality props. CSM is modified DX belts that are designed for show accuracy, updated features, and a much more affordable price. CS is the "definitive" belt for things like Rider 1 and Kuuga, but CSM handles many of the current Heisei stuff.
As an example of updated features, the Decadriver has sounds and cards for some post-Decade riders. It also has a button to play 2 different bgm pieces at the bottom of the buckle. The Faizgear has an updated set of tools and expanded sounds.
That's not to say they're perfect. When doing the W gaia memories they initially forgot to put a metal color on the usb bottoms. Decadriver doesn't have any ability for future rider expansion so it was out of date already when it shipped. But if you're looking for any of these items (plus a potential Black belt), I'd strongly suggest going in at this level if you want more than just a toy.
