I have a lot of glass and all tile floors. Room treatment is not an option as this is our main living space. Should I try a tube DAC, Tube Pre., tube Buffer? How do I warm up the sound I'm getting?Sorry, but it *has* to be room treatment. Nothing brings out glare at higher volumes like glass, and tile doesn't help. Changing your components out is completely barking up the wrong tree. You need a thick area rug over the tile and drapes or pleated shades at a minimum for the glass.
Take a look at the Stereophile test measurements for your speakers: Three things stand out: 1) the sensitivity is *very* low at 84.5dB (your Butler TDB 2250 should be a great match as you say); 2) this system is nearly devoid of panel resonances, so it's probably not cabinet colorations creating the forward sound; 3) the response curve is *extraordinarily flat*
Your other components are also very linear and if anything, the Butler and the PS Audio should be on the mellow side. Early floor reflections off the tile and side reflections from the glass are almost certainly the culprits.
There are many room treatment panels available now that look like hanging wall art or at least decorator panels. You really need to look into these, or you need to switch to a speaker that has no vertical dispersion to speak of and tightly controlled lateral dispersion as well. That would be a shame because you have a great speaker.