My preference for a preamp is both sound and function.
For the function I like / require at least 2 balanced inputs.
For sound I prefer a class A operation with 6SN7 tube complements and a tube rectifier. I also like lots of dynamics and drive. I have never heard a solid state preamp that can project such a large and deep sound stage.
With the right tubes and rectifiers coloration is minimal and refinement is high.