They'd have to be happy owners to begin with, which says something.
If I was a tartan owner, I would want to brunt the damage to the value of my boat by posting my good experiences.
I doubt the manufacturer would solicit this stuff but I could see the dealer putting out the word, they have a more personal relationship with the owners.
Not to mention an interest in continuing to sell new boats.
hunter Legend 37 Semper Paratus
Formerly - Tartan 34C Yawl