I have good experience with them, they did the mod for me too. You guys make me feel bad I don't have the GX16 connection! I have the barrel connection at the 218 side. There is different levels of cables from Farad. I did hear a very small difference between their DC cables. But these differences are small relative to the gain of the PSU itself. If you want to get the last drop of performance than go for the fully specced, but the standard option is already a great improvement over the SMPS inside the 218.

Main: DSP8000SE< 218 < Farad Super3 TMCB < PS Audio P10. Room correction: Focus Fidelity.
Second: Fostex Fe206NV2 < Audio innovations 500 valve amp < Wiim Pro +
Study: DSP33 < Reviver < MS200
Server: ROCK + Tidal on NUC, fiber on 2x cisco 2960, HD-Plex LPS.
Gone: DSP7200SEu, DSW, DSP5500mkI & DSP5000mkI, 508.20, 210