Hi Matt, you are right... While Criterion is far from being a "bright" pre, it does not share the slightly dark golden house sound of classic Rowland products from the 1990s and the earlier part of the 200X decade... Fact is that, with some exceptions, the "dark Rowland sound" is becoming a bit of a charming urban legend.
On the other hand, I expect that Aeris's juvenile exhuberance in the treble region should start to be reabsorbed once you pass the 450 hours mark.
Concerning Final Drive and its transformer coupling... It is worth pointing out that both Aeris and Criterion have trnsformer-coupled balanced I/O... on Aeris transformer-coupled input is the SPDIF 75 Ohm coaxial. Conversely, Veritas inputs are not transformer coupled as far as I know. G.