I have heard all three, The 7.5 on loan in my system, and owned the K-1XE. These two are very close. I slightly prefered the little sweetness of the VTL in my system. (but not enough to switch from the K-1XE) However my wife and most of my friends liked the overall presentation of the Ayre better. IMO the 7.5 and Ayre are on an equal playing field.
The Ref3 I have only heard in my friends system. Many times, but never at my place. It is alot better than the LS25 MKII he had before it. I am not the biggest fan of ARC gear. But his system sounds good with the Ref3 in it. I am sure others will add more than I can.
If the K-1XE is really good in your system. Why not sell it and take the money and buy another one used? You can then run all three balanced. No money lost and your problem will be solved.
The Ref3 I have only heard in my friends system. Many times, but never at my place. It is alot better than the LS25 MKII he had before it. I am not the biggest fan of ARC gear. But his system sounds good with the Ref3 in it. I am sure others will add more than I can.
If the K-1XE is really good in your system. Why not sell it and take the money and buy another one used? You can then run all three balanced. No money lost and your problem will be solved.