ARC Ref 6 VS. Vac Renaissance MK V

Have heard the Ref 6. Was super detailed and transparent but very forward. Have not heard the VAC preamp. Thoughts? 
Has anyone compared the current stuff like VAC master preamp directly w arc ref6, ref10?
I’ll probably be borrowing a VAC Master from my dealer soon, to compare to my Ref 6. But I saw a photo of the inside and it looked a lot like the Ren V circuit, with the main difference being PSU (much in favor of the Master). The Ren V SE might be an interesting option, since based on the SE vs. non SE on the Renaissance phono stage it raises the parts quality a lot (I think even better than Master in some cases) and makes it sound more neutral and detailed.