I've owned all 3. First the Havana, then the Calyx, then the Octave.
Now I am using the Havana in a highly modified form -- pretty much all caps replaced, several with V-Cap CuTF, DAC chips, power transformer, diodes, key resistors, WBT silver RCA outputs, BNC input (all parts replacement, no alterations to the board). There is a huge MHDT Havana thread on Head-Fi that goes over all of these mods. I never sold the Havana but bumped it down to a second system; it has special qualities of timbre, texture, and PRaT that are unique IMO, but lacks a fair amount of detail, dynamics, extension, and authority in its stock form. Now it is back in the main rig and is easily the best DAC I've owned, which includes both Berkeley DACs. The heart and soul of the original is retained, but the shortcomings are all rectified and the strengths are improved upon greatly as well. It is also nice that you can tune the sound by replacing certain caps and of course the tube. The Havana is quite responsive to changes.
To answer your questions, based on memory...