Serial Cable Connection for Sk880/WK8 keyboards

As you may all know, GeneralMusic sells an accessory for WK/SK series keyboard which is the serial cable (I do not know if it is standard) that connects a computer to the keyboard. Well, one salesperson warned me that it is not reliable and a regular midi adapter is the way to go. I would like to know of any opinion regarding this.

George Kay? Chris Anthony?

I'm not sure about reliability issues but as I recall the serial "to host" connection only gives you 16 midi channels verses 32 if you can use regular midi cables into a multi port midi interface. I know on my WK8, you can select PC1 or PC2 the difference being PC2 gives you 38400 baud and PC1 gives you 31450 baud transfer speed. I would think if there are reliability issues it may be due to selecting the wrong baud rate for the PC. I would think you could use 38400 with your setup. I have a 333 MHz system and 38400 would be fine with the uart on my motherboard.

Who sells this accessory and for how much?