Hi Carl,
Usually you (in the US) and me (in Oz) are the other way around ....you have managed to hear everything, possibly even in your own system, and I just have to read as much as I can and take an informed guess.
Unfortunately, words on a screen cannot convey the true sound of a component. Especially when they are written by someone you don't know, who listened to the component in a system you don't know. So you have to take what anyone (including me) says with a grain of salt. However, let me pass on the little info I can, in the hope that it can be mixed with the other grains of salt and be of at least a little use to you
My reference of the last 2 years has been the BAT VK-30 tube pre-amp. I added NOS tubes which certainly improved it. However, the GK-1 has been a revelation. It is *so* much better than the BAT in virtually every parameter that it is not funny. As we upgrade, finetune and tweak our systems, we expect the improvements to become smaller and smaller. Well, the GK-1 has been one of the two biggest improvements I have ever made to my system (the other was when I replaced my Rotel RMB100 monoblocks with a Plinius SA100/3 a few years back). Yes, the BAT was US$3500 and the GK-1 smoked it. FWIW (not much) I have read of audiophiles comparing the BAT VK30SE and VK50SE to the VK30 and finding them better, but not much better, and the VK50SE costs a stack more than the VK30.
I've heard pre-amps in my system from : Arcam, Acurus, Golden Tube, Rotel. And others in decent systems but not my own from : Electrocompaniet 4.6?, AI M3A, Musical Fidelity, Perreaux, Golden Tube, Arcam.
Not one of them grabbed my attention and made me immediately think to myself .....aahhhhhh this is it !! This is REAL music. None of them kept me totally involved and unfatigued for listening sessions lasting up to 8 hours long. None that is, until the GK-1.
You have probably read comments from Darl (aka Pleb Plebian) on this forum, comparing the GK-1 favourably to pre-amps from Mark Levinson, the Audio Research Ref 1 and others. These are all well reputed and $$$$ pre-amps. I think one or two people have also replaced their Bottlehead pre-amps with the GK-1 (perhaps someone else can confirm this ?).
Unfortunately, we tend to look at the comparitively cheap pricing of DIY components, and immediately think that they must only be good "for the money". Perhaps most are, and over-enthusiastic reviews and bold claims made without real premise do DIY in general more harm than good ? No doubt some readers, not having heard the GK-1, are reading my very positive comments here and thinking I'm doing exactly the same thing (shrug). So unfortunately, when a true gem comes along, the baby is thrown out with the bath water
All I can say is, find a well-put-together GK-1 and listen to it for yourself. It wasn't until I added the GK-1 that I realised how good the rest of my system really is.

My system:
Sony SCD-XA777ES SACD player
Aspen GK-1 linestage
Plinius SA100/3 power amp
Ambience Ultra 1600 (Australian ribbon/hybrid speakers with Hovland xovers)
PS Audio Ultimate Outlets (High Current)
Eichmann AC cables (replaced Synergistic Research AC Master Couplers)
Symposium Rollerblocks & Vistek Aurio MIB's
DIY constrained layer platforms
Dedicated AC lines (240v/20A, 10awg)
Room acoustic treatments