Singer Color Changer

Can someone speak to the Singer 4 color changer accessory in more detail?
Does it work well, Do you use it & Like it
Are they hard to find? Expensive?
Worth getting or not?

I have read all I can find on the color changer between here, Patrick’s site & the Vault and am not sure of the following:

Do you lose any functionality or adjust-ability of the knitting carriages or knitting beds by using one?

Does the Color changer’s yarn carrier also replace the standard “2nd yarn guide” normally used with our machines? (I am thinking yes) And does it work as well as the standard 2nd yarn guide or better?

Thanks for your input.