I have lived with Avantgarde Duos for more than a year. I think they are great - extremely dynamic with exceptional timbre and resolution. They have great definition, and there is no horn coloration as I have heard in the past with other brands. The high freq. are light like electrostatics and the 225 sub woofers are very fast and go down to the basement I like the volume and cross-over controls on each subwoofer very much.
I have listened to other high end systems for hours on end, and I would suggest that these speakers are clearly class A. I don't believe in "best designations" at this level because personal preference and musical tastes have great influence.
Also my wife like the looks - and that is saying something. They are a conversation piece. Other hi end audiophiles have enjoyed them in my home as well.
It is important to have a good room as starters. then comes the associated equipment. With regard to components and cabling - everything counts. This system is unforgiving for noise. Noise is amplified by 10dB more than most speakers. I use Cary 300B SE/SLP-98P, Nuvista CD, VPI / SME/Clearaudio analogue. All my wiring is pure silver (cables and interconnects) including custom speaker harnesses. I believe these cables and interconnects have made a huge difference in the sound - more open and airy than with hi end copper in my experience.
A recent great addition this week has been absolute power cords throughout the system. These have really knocked down noise level in the system and optimized base and imaging. I can't believe their inexpensive price.
I would also suggest that dedicated power circuits to minimize AC power noise is a must. I set up two independent dedicated circuits, one for each channel off both sides of the 220V source. This is a poor mans balanced power set-up described by J-10. I expect to get a new power conditioner, probably an equi=tech Q series this year to kill the last bit of noise.
One great advantage is the speaker directionality. They minimize room influences tremendously - and that is a very nice feature in real world listening rooms.
Would I buy these speakers again? Yes, without hesitation.