A fair number of E-175s use C (mostly C-North) and I wouldn't book away from an otherwise-convenient itinerary with an IAH connection just because of a threat that the TerminaLink won't work. As we have seen, the system has its moments, but on balance it seems to be more reliable than other systems (such as the EWR AirTrain). Of course, once bitten, twice shy, but your criteria would eliminate IAH as a connecting point for many itineraries.