Interesting topic. It seems like this question reprises itself in some incremental variant form every few days or weeks. I have the MPS5, dCS Paganini, Esoteric rubidium clock and the Boulder 2020 on hand right now. Owned for 6-18 months: Esoteric P03D03, dCS Elgar plus, Wadia 921/931, Esoteric D05 in the last 2 years. I would say that the Wadia, dCS Paganini and MPS5 are somewhat orthogonal to each other in sound (imagine a multidimensional relation rather than the so-called Type 1, Type 2 flavor in another Agon thread).
My impression is that the Paganini set, clocked by Esoteric, is much clearer and with better air and resolution than the Elgar plus stack but it has been some time. Oh, and I had the Zanden Signature DAC and still the Mark III...
The one DAC I have been tempted to try is the MSB...but one can only have so many digital systems without being overly nuts!