As far as I can recall, sir, the difference is considerable but its not highly significant. Its not what you might call night and day difference. Medyo manipis ng konti yong stx, but soundstage is quite decent.
Sir, what Im really after is the combination of the two: stx soundcard as transport (bridge) and Rega as DAC. I would presume na kaya maganda yong result para sa akin, kasi Rega is known to have full bodied sound tapos it is receiving signal from manipis ng konti = sakto lang siya.