Realize you're looking for Spirit 3 versus 2 owners input, but what the heck here's some info anyway
Have the Spirit 2 with Black Treasure KT88s (like the 3), and also have NOS RCA black plates in 2 rear 12au7 positions and NOS CIFTE Mazdas in the front 2 positions for what any of that may be worth knowing.
I haven't heard the 3 to know how much of a difference the parts upgrades have made in the musicality of the amp , but have used the 2 with JM Reynaud Offrande Supremes (monitors), and Tyler Decade 3 & Tyler Linbrook System 2 floor standers and have been very happy with the synergy and sound.
Have the Spirit 2 with Black Treasure KT88s (like the 3), and also have NOS RCA black plates in 2 rear 12au7 positions and NOS CIFTE Mazdas in the front 2 positions for what any of that may be worth knowing.
I haven't heard the 3 to know how much of a difference the parts upgrades have made in the musicality of the amp , but have used the 2 with JM Reynaud Offrande Supremes (monitors), and Tyler Decade 3 & Tyler Linbrook System 2 floor standers and have been very happy with the synergy and sound.