Boutique/custom vs production tube linestages

I've owned all manner of production tube preamps.

Lamm
ARC
CJ
deHavilland
Audible Illusions
BAT
Cary

I am currently using a Don Sachs preamp which is certainly about as boutique as they come. I never compared it directly with any of the above, as it replaced a passive LDR preamp that I had at the time. But I can say that it is a fine sounding preamp and I have no desire to go back to any of the big name companies. 

As @blackdoghifi talks about above, customization is a big part of going with the little guys. It's not cookie cutter and you can get what you want. And most of the time, you get better parts quality than what  you get with the big guys.

Oz

Thats why I liked working with Matt at Toolshed.  Mine will be a 3oob but will have a few upgrades like stepped Khozmo attenuators.  Upgraded output trannys,  silver foil coupling caps.   Transformer covers will be dark bronze hammertone.   Amp uses 0.5 % tolerance resistors throughout.  Rosewood/Figured Cherry base.   

B.O.M. is better than most anything in its price.   I spoke to a few Toolshed owners and they said it was the best amp they've ever owned , and their list of former amps included all the big boys.  Many which are beyond my reach.    

Wow Toolshed looks impressive, would like to see them offer separates or do they.

Truely a work of art.

Toolshed has a preamp too ....

I have done some testing in this space as the importer for Art Audio and one of the importers for KR.  I have had A LOT of preamps here.  Some from big companies.  Some from little companies and in the end, it comes down to matching with your power amp and personal taste. 

I ran the Art Audio Conductor for a stretch and it sounded better than any other preamp I have had here with Art Audio, VTL and Rogue Amps.  When it arrived I had a PS Audio BHK and an ARC in on trade and a variety of others through time.  It has switchable gain from an active circuit with no gain to 25dB of gain.  So long as I was matched with a power amp where that made sense, the sound was incredible.  Give me an amp that was in the middle and performed best with 12dB, results were not as good.  

If the designer knows what he is doing and the components are well selected, a small company can do an incredible job.  Often, you can get some really great designs or really different approaches that you won't see from a bigger company (KR P135?????) which can be awesome.  

But, you have to vet them.  Is there a service center?  Are the parts really esoteric or is the equipment pretty mainstream?  Are they truly making it by hand (point-to-point wired) or is it PCBs that are being assembled.  Talk to certain manufacturers/importers and they will tell you point-to-point wired is the only acceptable method for production and PCBs are garbage.  Talk to certain repair shop and they may disagree rather vehemently.    

In the end, it comes down to the individual company.  Unless it is silver wired, I look for amps and preamps with PCBs (not a lot of silver PCBs out there) where the output specs are what I need for my amp.  That is where I start and then it comes down to the tube compliment to determine if I think I want it with my amp.