Raidho, I own Marten Coltranes and have heard Avalon's mid-range speakers. I will say this, they (Avalon) are beautifully made with care and attention to detail. Avalon have taken a leap forward with new speakers including the Compas Diamond and Tesseract (from which the new advanced drivers are filtered down). And actually, for Compas Avalon are using newer model graphite-coated drivers than Tidal.

Marten is a level up on Avalon? The comparative speaker price-wise in the Marten line is the Bird 2. Bird 2 is using older, less sophisticated Accuton drivers, lighter less sohpisticated cabinets and use more "off the shelf" parts compared to the Compas Diamond. I've heard the Bird 2's a few times & preferred the sound of the Avalon Transcendents (two models down from the base model Compas). Btw, my Dealer stocks both speakers and to me the Compas Diamond was a no brainer, and about $18k cheaper than the Contriva Diacera SE. The Compas Diamond is a spectacular sounding speaker! The Marten Coltranes otoh are a different kettle of fish & are amazing