Mr. Bill,
I have no experience with the MIT & H2o together. However, in the past I had used the MIT 750 Series 2 biwire with Theil 3.6's and McCormack DNA-Deluxe. As you state, there was no loss of low level detail... It was there and fine. I ended up making and audiophile "adjustment" and ended up with Martin Logan SL3's, same amp, same MIT cabling. Still sounded alright. Looking to make a swap to tubes, friends came over with Sonic Frontiers SFS-80, Music Reference RM-9, as well as a Conrad Johnson model I can't recall. I can tell you after swapping all of them in and OUT, everyone was scratching their heads. Two friends *swore* it had to be those damn MIT boxes and one drove home and brought back a pair of Synergistic Research speaker cables (No. 2 or No. 3 if I recall) and it was amazing, every single ONE of the tube amps there sounded MUCH better than the big McCormack DNA-2 Deluxe with the MIT... actually we then tried the DNA-2 Deluxe with the Synergistic as well, and it was much better. All we could come up with is the box must have caps and such that "adjust" or "tune" the highs and lows to affect the sound for SS amps that may be bright in some systems. It was definately affecting the sonics in my system.
Disclaimer: This was well into the past... about 8 years or so ago, perhaps 7. However, after that weekend - I listed every MIT interconnect and speaker cable for sale, and will never consider another again.
Don't get me wrong, I have heard them sound quite decent on a Krell or Spectral / Avalon or Thiel / MIT system, however detailed, sterile, analytical doesn't appeal to my musical tastes... at least not anymore (that is what got me hooked initially).
All in all I guess I am just trying to relay almost all cables have strengths and weaknesses. Some more than others, I assume. In this case, I know there were "major" sonic landscape shifts with the comparison of the MIT cabling with tube gear compared to Synergistic Research.
Perhaps the MIT boxes adversely affect the H2o. Like I said, I don't know personally. I know the MIT boxes did adversely affect the SFS-80, Music Reference RM-9, and those Conrad Johnsons...
At the summit, it usually does depend on overall synergy of equipment to bring out the best in each component.