I somehow picture that most advisors/companions see Cullen as really positive person. And somehow Cassandra's subtly supporting him mentally with that problem he face on his personal quest. She's keeping an eye (or two) on him on their agreement right?
Cole's really like Cullen apparently 
Blackwall holds Cullen very highly (he had such a sad line about Cullen probably not wanting to have anything to do with him, after his personal quest). Iron Bull really respects Cullen, for all the teasing he does (he mentioned several times to me how Cullen was a good man, a good general, etc). Sera and Dorian talk about Cullen like he's a puppy and your relationship with him is more amusing than anything. Varric has the whole "Curly's just here to look pretty," but I get a sense he respects Cullen for surviving Kirkwall and still retaining his sanity through it. Vivi had zero opinions on Cullen, but I totally headcanon her poking fun at my Quizzie for dating a dog-smelling Fereldan everyman, such a quaint match for Lady Trevelyan's high state as Le Inquisiteur.
I don't remember now what exactly Solas said about Cullen the one time he mentioned him, but I remember it was a slightly backhanded compliment, something like he's a nice guy for a Templar. Cassandra definitely likes and respects Cullen, as we can see through his personal quest.
And then there's Cole. Cole has such a baby crush on Cullen, I can't. I joked once about Cullen being Cole's indirect ghost daddy, since my Quizzie mothers Cole so much, but I think Cole really wouldn't mind that notion, calling him soft and gentle all the time. Papa Cullen has such fluffy pauldrons to snuggle against, after all. 