I use a Dreadnaught with a Theta Casa-Nova pre. No complaints here. I fear a Classe pre may color the signal a bit (warm). I've owned two Classe pre-amps in the past. I would recommend taking a good hard listen to the Theta Casa-Nova they are going for very cheep right now in the used market.
Sorry never owned a Plinius.
Sorry never owned a Plinius.