Yes, the interface is a big pro to the XT.
I mean on paper the Blofeld seems to have fewer artifacts and higher resolution filters. My guess is the DAC is superior but maybe not the line amps (which is equally important). Certainly the line amps on the Quantum seem a big step up.
In any case, the XT has a kind of low midsy veiled quality going on even when things get crazy which I think is more musical than the Blofeld. You often don’t need the 2nd filter to mellow things out. Can be harsh in patch design but not harsh to the ear.
I also prefer the XT’s digital filters to a lot of recent vst filters, even though the tech is much older.
Of course, like I implied, the Microwave I has the best raw sound, but is limited in comparison in terms of filter type (same with Blofeld to lesser extent) lack of 8 stage wave envelope, and interface again.