Solid State preamp Brands

Following with interest. I have tried Schiit, Ayre and Coda, but settled on a Pass XP-12 to mate with my Coda #8. I am always on the lookout for a step up and am interested what others have to say about the Classe. 

Benchmark (and Holo as on your list).

I have a Coda #8 with a Holo Audio Serene KTE and it was a wonderful match. Just sold it yesterday for a NEW BAT VK-80 tube preamp. That pairing brought me to a NEW LEVEL. All great equipment!

It might help to know more about what you need, such as remote control, balance control, any other features and function, and price range.  It's been a while since I heard your candidates, but, I liked Ayre and I owned, and liked Coda.  However, I've heard stories that quality control has suffered just a bit at Ayre after the death of its founder.

Nagra makes some nice linestages that sound quite good and work well with solid state and tube amps.  You can even get them with transformer inputs and outputs.  I have tube gear with transformer inputs and outputs and I like the sound of a lot of iron in the path.  

I'd add Pass Labs to your list.