Generally negative
Complaints include an LED that doesn't appear to light up, a non-customizable surround button seen as wasted, difficulty exiting registration mode, and fewer style variations per rhythm than a competing model.
Frequently criticized
Users are uncertain whether an eight-track sequencer exists and compare it unfavorably to Casio's own XW series sequencer, calling the execution poor despite marketing.
Frequently criticized
Users report it's not possible to quantize played notes, which they consider a serious shortcoming for a keyboard with recording features.
Frequently criticized
There's no way to record a drum track or other sound and play it back in a loop, limiting the usefulness of multitrack recording.
Strongly criticized
One user could not get wired or wireless adapter MIDI to work despite following setup instructions correctly.
Generally negative
A buyer of both the CT-S400 and CT-S500 found official compatibility listed only for Windows 8.1 and 10, raising doubts about Windows 11 support.
Generally negative
A user had issues playing MP3 files from a USB drive and was unsure which USB type is required.
Frequently criticized
One user described the AiX-based tones as plastic and unnatural, calling it typical of a cheap keyboard and saying sound presets need heavy tweaking to be usable.