Rega Saturn or Marantz SA-15s2 to upgrade CD play?

I currently have a Rega Apollo, and considered upgrading to Rega Saturn....Several reviews notably claim the Saturn is better than the Apollo. I was told that the Marantz SA-15s-2 is smoother, more musical, and with better bass authority or slam( those areas is what I am looking to improve over the Apollo).

Need some input and advice from members who are familiar with all three CD players, or own the Marantz noted If the differences are only marginal, please let me know. I am on a retirement budget Thanks