There are definitely some positive aspects of a CFS-C upgrade regarding the K1Max.

I recently purchased a CFS-C for my K1 Max(2024 late version with unicorn nozzle) that was running very well for the last year. I was very sceptical reading all these bad reviews, but I can say I am very happy I upgraded my printer and I want to talk about it since most satisfied users just forget about it.

Positive:

1. Very easy hardware installation.

2. Installing firmware using the usb provided was also easy. I had to upgrade the firmware to the latest version afterwards using again a fat32 formatted usb stick. The firmware upgrade for my printer(Not the latest pcb) was available only with the usb method(Not OTA).

3. The filament waste is very small. Previously I would try to make some multicolor prints manually(Engraved text or logos for a couple of layers at the bottom or the top surface) using the "PAUSE" command either from "creality print" at the layer start or inside a layer by changing the g-code with "text editor", and I was throwing away much more material and time. Changing filament in multiple layers is definitely a waste of material and time but the result is also not well for an fdm printer in my opinion and I avoid it anyway, so a tool changer that is better suited for this concept would produce minimal waste but equally bad quality results.

4. Creality Print is a very good slicer. I have been using this slicer from the beginning and I am accustomed to it. Trying other slicers recently I found no real advantages over this one. I enjoy making my own CAD files and turn them into physical objects and I am less interested in tweaking the printer properties etc. The K1 Max CFS-C is supported in the slicer properly and I think there is space improving it even more by providing some more official settings and include more nozzle diameters and filaments.

5. It has been very reliable until now and I had zero failed prints with it, printing PLA and ABS. I don't have an enclosure yet so the ptfe tube is moving freely passing through the top of the printer.

6. It is a very well built and good looking machine as is the K1 Max.

7. The firmware update gives an elegant feeling and great management of the filament spools(CFS-C spools or Side spool) through the printer' s screen or the "Creality Print".

Negative:

1. The price is non optimal at 260 Euro.

2. You lose some functionality. For a stock printer like mine you don't loose much but there is definitely some. I cannot see my printer through the browser like before so I have no clue what is going on with the bed mesh. The automatic calibration is also limited to the bed leveling and input shaping. The LIDAR module is not working and all the functions related to it are gone. I didn't see any great difference when it was functional anyway and the manual calibration of the filaments you use is considered better in general. Having a dead module is not great though and it's availability should be restored with a future firmware upgrade.

3. There is some routine running when a print starts that is trying to use a wiper(I have no wiper but I tried to install one). I think it is something that needs to be adressed by creality. The wiping routine is locked and you have no control. Currently it moves left and right without touching the plate but digs too much inside a silicone wiper if you try to use one. It would be great if we could have some control through "Creality Print" over the wiping position and when the wiping is happening.

4. The prime tower needs to be refined. You can reduce the tower' s size to a very acceptable level by changing the flushing volumes but there needs to be much more flexibility there. Also the changing filament procedures need to be refined. There is some excess filament stuck on the prime tower when a change happens that sometimes can be dragged to the object you print.

5. The PTFE tube provided is barely enough for the K1 max and it should be at least 10 cm larger. It works but it just feel restrictive.

6. The lack of an active dryer is a negative also. The chamber is common for the filament spools sitted inside so maybe there is some reason. As a drybox it works very well but you need to dry your filament spouls beforehand, preferably through a SpacePi x4 so you can put them inside CFS-C fresh at once.

Summary:

The CFS-C works very well with the K1 Max and the filament management and multicolor capability is very welcome. More filament, nozzle size and plate type settings should be oficcialy provided inside "Creality Print". Some firmware updates need to be released so the previous automations can be restored and even enhanced.