Big Difference With New Source?

I am considering upgrading to a new cd player. My modest system has slowly come together and at this point I figure the cd source is the weakest link. Currently I have a NAD 541 w/hdcd. I am considering players in the $2k range from Linn, Cary, Rega, Naim among others. My question: What differences am I going to notice compared to my $500 player. Will there be a major, dramatic improvement or will the changes be more subtle. (Will I have to concentrate to hear the difference?) I would appreciate your opinion. --------PatrickSYSTEM: Bryston 3bst
VTL tube preamp
B&W CDM1nt
NAD 541 cd