Is it worth to buy a used Meridian 506.20 ?

I have a 506.20 and absolutely love it. What don't you like about the CD-72? What do you consider a good deal?

Someone is willing to sell 506.20 for $550 and 508.20 for $750. The high's with Arcam seems to me is controlled. Also
I'm listening to jazz and vocal and would like a player which can make background little bit darker. Does this make sense ?

Sure does. I also listen to jazz and vocal and it does an excellent job with soundstaging and tone. You will like the build of the Meridian. The drawer is solid. I can't speak to the difference with the 508, but $550 is a great price. You won't be disappointed.
Meridian 506.20
Classe CAP-151
PSB Stratus Mini
Kimber cables

Thanks for your response. I think I'll get the 508.20 and have the option to upgrade later.