It's a sideways move, imho (perhaps even a slight downgrade).
Yes, you already have a very good cd player there. I remember people used to compare it with the more expensive and highly regarded Rega Apollo.
I had the MF VDac for a while, and while it was a definite upgrade to the SuperPro 707 DAC I used before, I would rank it several notches below the Rega DAC I'm using now. So relegating the Rotel RCD 1072 as transport to the VDac will most likely be a downgrade, not an upgrade.
If you must buy a DAC, I highly recommend the Rega DAC. After reading a lot about it in internet forums, I waited many months until the local distributor could bring in some units. And I'm glad I waited
.