High end stereo preamps? Worth it?

@emergingsoul,

if you must have a preamp, look at a used Graaf 13.5b II. at least you‘ll have a balanced connection to the amp out of it. it still won‘t get you remote control, though.
i

Lowtubes,
thanks.

Sp11 mk11 looks great.  

My challenge is deciding between a McIntosh c1100 vs audio research ref 6se.  Thoughts are welcome.
Why have you pursued such a large volume of hardware? So much expertise, and great it’s being shared.  I am hoping to make this a final purchase and go into retirement from my pursuit of overpriced audio equipment, all links in my chain will be quite strong at this point. 

I actually do both - main system is a Benchmark DAC1 and Sonic Frontiers phono stage into a BAT VK51 SE (the 6H30 tube is remarkable!). Second system is a Benchmark DAC1 HDR directly into an Audible Allusions amp. The pre is important in my main system for buffering the phono stage. Overall, having the pre is better, and I only don't use one in the second system out of convenience.

Emergingsoul,
               Im not familiar with the Mac and AR preamps you mentioned above. I would seek out a online McIntosh community of owners and get their opinion on the c1100 and same for the Audio Research of community owners on their take for the ref 6se.                I’ve collected stuff throughout the yrs. I have a few of extremely well regarded preamps because I chose to pick up a few of the best picks from audiophile friends that they’ve heard.  Each one of my pre’s has its own unique character, but a thing that I have noticed that separates a reference preamp from a very good pre is the size of the presentation.  A truly reference preamp is gonna be EXTREMELY open to the point where one cannot detect its boundaries and it will throws a gigantic soundstage with great dynamics. So as you’re evaluating preamps, I would take note of its openness.  It should sound like there are no walls or boundaries to the presentation. This should not only be evaluated with loud playing or certain tracks, but most importantly the music should have absolutely no boundaries even at low level and this should be evident on all the different types music played.            

What makes them worth it? What  qualities, preferably not expressed in purely subjective terms, makes a high end preamp that?
If I were to observe that a well designed $300 DIY preamp was indistinguishable in group blind testing from a Halcro DM10, and actually measured better, what would your response be?