The Opera is outstanding - it ended my amplifier merry-go-round of some 20 moderately-priced amps (mostly solid-state or digital) and sounds best with its stock tubes.
Extremely natural, warm but not syrupy, harmonically rich, textured bass, extended highs, and a big holographic multi-layered soundstage. A big step up from the Arpege Reference, which is also a very nice sounding amp, albeit a bit rolled off in the highs and less-defined bass.
As jbello is fond of saying... "trust your ears", and try to audition it in your system. Haven't heard the Recital though...