I have compared the Mephisto to Luxman m900u (on TAD CR1), the Colosseum to the Burmester 956 (on Kef Blades and Gryphon Pantheon speakers), and heard the Antileon Evo Sig on its own with Dynaudio Temptations.
I think Vitus has the better tone, density, that class A liquidity and fluidity, while Gryphon has more speed, detail, and jump. Annapolis Raider had both and chose the Gryphon, Audioblazer on WBF chose Vitus after having both.
I have never directly compared the D’Ags but they remain the best amps I heard the Alexandria X2S2s with. So I think Adam’s shortlist is excellent.
So my top SS amps if I had the money would be D’Ags and Vitus, followed by Symphonic Line Kraft (rare in the used market, class A 3400 – 400w), and Luxman m900u (cheapest good amp if you cannot afford the higher priced amps). Loved the Berning Quads but not sure how well they drive tougher loads.
IME the Kraft showed a much higher delta to Burmester 911 (on Magico S5 and B&W 802 D3) than the Colosseum did to the 956. It had all the attributes of class liquidity and fluidity with speed and bass. Problem is availability and distribution