From what I gather from all these replies people's main concern is that FreeBSD is generally harder to use/configure and management is hard to persuade into supporting it because it would make DevOps less productive.
From the standpoint of a person who run FreeBSD in production on both bare metal and VM's and manages several commercial applications and websites, I must say that plenty (if not all) of these phobias are unjustified. Yes, there are some edge cases but 95% of the time, there's nothing new to learn you already don't know, except new package manager commands and slightly different file system layout.
Not using awesome technologies like ZFS, Boot Environments, Jails, Qjail, Poudriere and awesome PF is just a plain missing out in my opinion.
I personally don't care about desktop, there are already 2 awesome OS's that majority of people use for a reason and that's pretty much enough I think.
I personally heard nothing but praises from people who are long term Linux users/admins who tried it.
Once people figured out couple of OS specifics its all breeze :)