oppo 205 vs sepearate DAC or CD player.. should I bother?

I am currently using an Oppo 205 as my digital source, and I primarily listen from classic Rock to heavier music. Sound Garden, NIN etc.

Are differences in these recordings even worth going for a stand alone CD player or DAC?

I recently picked up a ML 326S pre, and I am tempted to look for a used 390S to match. The 512 is way out of the budget. I am thinking 2-3k.

System is listed under my systems.

thanks.

Brian