@meiatflask - There is something special about the ZOTL design from David Berning that provides amazing clarity and 3D soundstage. I was using my Cary at the time when a friend brought over his MZ2. The difference was immediate, like replacing new glass in place of a piece that needed cleaning. I placed an order the next day and sold my Cary.
I'm still using 2 of the NOS JAN Sylvania 6SN7GT tubes I had in the Cary for the MZ2. The Cary's NOS Telefunfen 12AX7s went into my LTA amp. I could have deployed the Cary's 12AU7s also in the MZ2, but it can use 12AT7s as an option, which I prefer. The 12AT7 provides a bit more gain and a more forward presentation depending on the brand. Again, the MZ2 is a tube rolling funhouse. The stock tubes that LTA provides sound pretty good.
I know that LTA has also just announced a new/improved preamp for those wanting an even more refined sound, more inputs, a better volume control, and a more polished look. Its price is more in line with Cary/CJ
For me, I still like the MZ2. At its cost, I can't see how it can be beat, even when configuring with upgrades. Like the new model, the MZ2 is also a premium headphone amp, its originally designed intent.