I'm using the MicroZOTL by itself right now with my Zu Soul Supremes, and I'm shocked at how good it is with just 1w. I've used a number of Transcendent OTL amps with 2-5w and the scale that the MicroZOTL is able to produce vs. those is incredible. My Zu Cubes are at my cabin in another system so unfortunately I can't give you a direct comparison there with the smaller Zus, but I have no reason to think the smaller Zus couldn't be driven equally well. I do have the maxed out MicroZOTL with the external power supply and NOS tubes, but that shouldn't matter in terms of synergy.
I'm only on the 3rd day of break-in with the MicroZOTL, but it's already at least the second best combo I've had by itself--I'll do a better comparison to my larger Atma-Sphere MP-1/Thoress 845 SET monos (and it driving the 845 SET monos) once the break-in is complete in a week or so. That's about $30K worth of really nice pre-amp/amp gear, and if this is close at $2K, that's saying a lot.
I'm only on the 3rd day of break-in with the MicroZOTL, but it's already at least the second best combo I've had by itself--I'll do a better comparison to my larger Atma-Sphere MP-1/Thoress 845 SET monos (and it driving the 845 SET monos) once the break-in is complete in a week or so. That's about $30K worth of really nice pre-amp/amp gear, and if this is close at $2K, that's saying a lot.