What improvements would I get with a "better" preamp?

@curiousjim   I have the BHK pre as well and really like it.  I think there are benefits to having a tube front end, with a SS output stage.  I am focused on room treatment next, which is very complicated since I know nothing about that aspect of audio unlike electronics.  My next upgrade may be the preamp, so this thread is great, but not sure any move I make would be any more than a sideways move.  

Someone ask the AI engine what hifi combo it thinks sounds the best and how much it should cost.

I dare ya!

I wasn't a big proponent of changing preamp vs power amp. I thought power amp will give you bigger improvement over preamp. This was until I put my new preamp in the system. I am not exaggerating, but it was a WOW! Everything improved. I've got bigger soundstage, more details and less grainy sound. I completely agree with @patrickdowns. Improved immediacy and dynamics. Improved imaging. In my case live and natural representation, the feeling like you are in front of  musicians or like you are in the studio. Music became more airy and easy flowing. I sat and listened for hours and I was re-discovering music I know by heart. Of coarse I am talking about tube preamps. Design is very important. Don't go for preamp with many tubes involved. This is a wrong understanding than the more is better. It is quite opposite. Look for good sounding tubes, capacitor-less design and high quality parts. High quality parts are bringing the refinement and microdetails in the sound. They can shape the sound too. They require longer brake in time, but the improvement is worth. In short a good preamp can bring big improvements if chosen wright.

In the above table (https://forum.audiogon.com/posts/2887705) I see in the lowest row mentioned an Ayre preamp. Where would a Bryston BP 25/26 be positioned in this table? And what strengths?

@vhond  I owned the BP-6 for years and according to James Tanner is very similar in design and sonically to the BP-26 outside the separate power supply and balanced inputs.  I can tell you it’s extremely quiet and neutral — literally straight wire with gain — and throws off a large, deep 3D soundstage.  It adds virtually nothing on its own and just passes on everything it’s fed completely unfettered, so in that regard in terms of the list it’s probably most like the Benchmark.  Hope this helps.