Highly interesting read, Joe. (If my voice would not sound like a rusted watering can and I could have chosen my dream-orchestra, the experience would still have been different, as Klemperer put the violins1+2 to different sides)
I have not much time to play these days, and am a rotten amateur. Still it has the one advantage - you change the instruments and love different ones if you do not play daily, but every 3 weeks or so.
Favourites right now are a self-modelled Kremsegg-Bechstein with a "condition" not like new and perfect, but from 0.30 to 0.75 or even up to 0.85, horrible for many of course, but if you were used to an old not-perfect upright it just does not disturb me - quite to the contrary, I love it.
Then I love the Kremsegg instruments, in particular Streicher Frenzel and Pleyel, Erard, but all of them; I deliberately change the Broadwood to a certainly "not-like-broadwood" thicker sound, as after a while I simply found it too thin.
For music that has more "bite" in the upper registers I like a modified K2 very much, and of course the D4.
Nice to read many like the Bluethner. I love those "warmer" (well, words do not describe music so well) sounds in theory, but I have no clue why I rarely play the Bluethner, for me something is missing. Maybe I just try to get the Bechstein from Kremsegg and others inte the "it has to sound fuller and warmer" park too. So - if you can't play often, at least you'll enjoy that your favourite instruments will change more .