Vacuum tubes have the ability to resolve this important sub layer of information to a greater extant than bipolar transistors. Not only that, but they can do it while simultaneously producing large fundamental tones without masking them over. The use of an output transformer tends to obliterate the critical sub layer. There is a marked loss of clarity and detail when comparing the OTL to a transformer coupled amp. By eliminating the transformer, the output tubes can be utilized to their fullest extant.
Much emphasis is made concerning minute differences in measured performance.
The point is that there is a lot more going on to music reproduction than these static measurements reveal. Achieving high reliability requires more than a good circuit. How the product is laid out has everything to do with minimizing failures. The Transcendent OTL was designed from the inside out. Most products today are designed from the outside in, assigning aesthetics as the highest priority.