People I played for, or with, on a regular basis were more likely to notice a change in my keyboard...also other keyboard players.

I think a lot would depend on what you used as your primary solo instrument on the arranger...for quite some time now, the main piano sound on all arrangers has been excellent, so if you played mostly piano licks behind your vocals or used it mainly on instrumentals, I doubt if someone would notice a change.

However, guitar and wind sounds only became dramatically better in the last few years, so a new keyboard may be more noticeable if you tend to use those sounds as well.

Ian