There is one consistent grey which looks fine. I'd say it's your file or method of creating it.
You might check your head alignments. They can get out of whack over time.
For an XC-540 that's about a standard print in my opinion. You might be able to improve it with alignments or you could try a new profile that is higher resolution and slower motor speed but at the end of the day, that machine is pretty old. It's about 4 head generations back so if you're comparing to more current machines, it's never going to look as good.