I have had VTL and ARC but not particullary the models you mention.
ARC brought a lot of a tube sound to my systemby that time, I found it a little grainy and not as dynamic as I would like to. VTL was more musical, all-around fine system which allowed me to listen to all kinds of musical material without any fatigue, but a little euphonic.
Hope this helps, it is a matter of personal tastes.
Fernando