Not a fan of their loudspeakers whatsoever and for the money, I could never recommend anything from that company... To each their own though. Preference is inviolate. After hearing the Duo Mezzo and XD, I’ve concluded that they are very forward and aggressive sounding. Regardless of program material or even volume, they hurt my ears to the point of a headache. However, that isn’t to say I wasn’t impressed with the dynamics of them. Both very expensive setups in large rooms with tube equipment. When I think of Avantgarde, Klipsch suddenly comes to mind and not the Jubilee (I actually enjoyed those). They can get ridiculously loud with minimal power though and put off a massive soundstage if you’re into that... Hopefully my comment isn’t offensive towards anyone as that is not my intent. That is my experience with Avantgarde though.
I’d be interested in hearing the Zero 1. Aesthetically, I find them to be rather intriguing and I’m pretty certain it is an active design.