Sonic Frontiers Hybrid pre amp question

Hi all,
I have an SFL-1 wich uses just one tube, the tube I am using is 1 of a matched pair of the 6201 nos tubes valvo/ Amperex from the Herleen plant in Holland from 1961.
What I am curious to know is, when using a one tube Hybris how much of a tube sound does this pre offer, is it somewhat of a middle of the road result from the hybris design, and what are this designs strengths and shortcomings?
In short how does this compare to tube pre amps with 4..6.8 tubes.
Also in close this has always seemed to be a peice of gear that was well respected so in the spirit of fun how much would it take money wise to top this pre amps performance? thanks for your time