other terrific (and i do mean terrific) low cost streamer option is the ifi zen stream, with an add on linear power supply, ideally at 12v dc, total cost about $600
i always assumed the pd creative ps upgrade for 2i node improved the analog out much more than the rca spdif digital out, as ps improvement tends to make the analog sound purer whereas digital bitstream benefits most from superior clocking (not affected by the p-s mod) and digital noise suppression (only somewhat affected) ... did you feel the rca digital out sounded noticeably better with the added mods to your 2i?