I have never moved on. I started with a CBIII and have upgraded it continually over the past 15+ years. In terms of audio quality, no other preamp processor comes close -- provided the new Extreme D3 DACs are used. It is just my opinion, but I think that the current Casablanca V is in the class of comparably priced Constellation, D'Agostino, and Pass Labs preamplifiers.
The catch with the Casablanca is the mounting cost of one's investment in it to keep it at a state-of-the-art level. Taking into account the costs of all of the upgrades as well as the cost of the Casablanca's original purchase, I must now have close to $50K invested in mine. That amount of money is hard to walk away from.
One other thing, Theta Digital's customer service is extraordinary. I have a fair bit of high-end equipment, and their providers (dealers and manufacturers) are generally quite good. However, with the Theta Digital Casablanca, one gets actual concierge service.