Anupmc,
Interesting that we both upgraded from the ML32 to the Boulder 2010. Yes, I actually did demo the VTL 7.5 in my listening room for a long weekend, shortly after I had the Halcro dm10 on demo. Just for the sake of completeness, when I did my demoing I had Linn Kimax Solo 500 monoblocks and my only source was a Linn CD12 (I had sold my old vinyl set up back then). And I had a 30' XLR run from the pre-amp(s) to my amplifiers (this is just the way my room is set-up).
I agree with you that I found the VTL 7.5 to be more transparent and musical than the Boulder 2010, particularly when going into the VTL with single-ended connections (Note, the 2010 as you know is only balanced). That being said, at the time, I did not find it to be so much superior to the 2010 that I felt compelled to switch. Perhaps if I had a set-up where I could have gone single-ended from the VTL to my amplifiers....
It's been quite a while since I had the VTL in my room, but to my ears based on my memory the darTZeel pre-amp is another cut above in terms of transparency, musicality, artifact-free, etc. It combines the very best of solid state and tubes IMO. Also, the unique 50 ohm constant impedance connection you can used between the dart pre and dart amplifier is audibly superior to RCA or XLR.
For the first time ever I am completely satisfied with my amp and pre-amp and am now turning my attention to upgrading my speakers (I have the Dynaudio Temptations now and will be auditioning the Magico 6's shortly) and my Linn CD12 (which I having David Schulte of the Upgrade Company upgrade for me as we speak).
Happy Listening! The VTL 7.5 is world-class in every way and you are undoubtedly very happy with it as you should be.
Take care,
Earflappin