While electronic design of preamps (or any component) is important, so is the choice of specific components… resistors, capacitors… etc. each choice makes a difference.
The head designer of one of the premier electronics companies (MBL ?) said, I can make a component sound whatever I like. If I want it warmer I use X capacitors… if I want it detailed I use Y resistors. I can make a component sound like anything I want.
So, the very best designers craft the sound to satisfy their clientele. This company decided there was a limited market (and appreciation for) for their very highest level products. So were creating a product line for the less discriminating tastes. I think there average component was well over $50K… so they wanted to get some of the chicken McNugget folks in the $20K range.