My Oticon IIC and CIC both also did not end up with a large vent even though my audi had written, as large as possible (again, I had them remade several times each time making sure it was specified). My Phonak vent is much bigger and nice and round, while the Oticons seems like someone manually cutting a sliver of a hole with a knife…
Also, for me (mild low conductive loss), I schedule to go into the audi to have my aid adjusted every two weeks for a total of 4 or so appointments. I have to have my aid set as the absolute lowest to begin with, and gradually adjusted up. Though I acclimate very well to louder/softer, the immediate loudness of the aid was not tolerable so this is the method that works for adjusting the aid for me.
I’ve also tried a Widex CIC (whatever their smallest ITE) and hated them, both fit and sound; don’t remember what the vent was like on that one.