Hi Maverick -
I have heard the vsi-60 mated with ProAc D15's and I really had no complaints other then I thought that the top end was kind of hot - which may have been cabling or the ProAc. Great bass, great soundstage , crystal clear and detailed.
One thing I would note that it did not sound "tubey" to me.
Please note that when I say that it is in relation to the Cayin A-88T, Cary SLI-80 as well as the SLP-98 running a CJ MV60SE, or any combo of CJ or Cary products I have heard.
I have no experience with the Ayon, other then word of Mouth.
In another post you mentioned that you currently own a Vsi-55. My guess is if you want a more "tube/lush" like sound, you may want to look elsewhere then the vsi-60 or find out more info on the Ayon.
What is your thoughts on the vsi-55 - I am looking into acquiring the VS55 soon, so would like to know your thoughts.