I went ahead and purchased the Ultimate Slim ICs. To my ears that they take all of the musical enjoyment that the Reference 2 brings and draws you even further into the music. I moved the Ref 2 into my 2nd system.
I am going to try the Ref 2 digital AES/EBU cable and see how its stacks up to the Mojo Audio digital AES/EBU that I presently have. The AES/EBU connection on my Simaudio 260D transport provides better SQ than the SPDIF RCA connection (I confirmed this with Simaudio) hence my trying the Tchernov Ref 2 cable instead of the Ultimate digital cable as it is SPDIF RCA.
I am going to try the Ref 2 digital AES/EBU cable and see how its stacks up to the Mojo Audio digital AES/EBU that I presently have. The AES/EBU connection on my Simaudio 260D transport provides better SQ than the SPDIF RCA connection (I confirmed this with Simaudio) hence my trying the Tchernov Ref 2 cable instead of the Ultimate digital cable as it is SPDIF RCA.