I'm a bit late to this thread, but from my experiences with my male Linnie (Machi) and female (Hiyoko),it seems like it depends on the individual bird.
For example, I can have Machi perch on my hand long enough to move him around, and sometimes I can get some scritches in. On the other hand, Hiyoko will only step up onto my hand if she needs help getting to where she wants to be, and she hops off as soon as she's close enough to do so safely. However, it doesn't seem like she has any issues with my hand when it's on something stable and she can snuggle up to it.
Both of them don't whistle, and this could be due to their ages, but Hiyoko is definitely more vocal overall, especially when she runs out of food in her container. However, she's mostly silent when it comes to being grabbed at the vet's while Machi will shriek the whole time (I shouldn't laugh, but he shrieked louder when the vet committed the greatest insult: examining his butt.)
It's definitely clear where each bird's priorities lie haha
As for sociability, it really feels like each bird has their own love language. Machi will press his beak between the bars or fluff up against them if he wants scritches, while Hiyoko....will come out and stare at us creepily if I'm pampering Machi at the time. Like I said before, she will come out and snuggle into my palm but that's basically it.
These two aren't bonded, but I feel like they do find companionship with each other. Machi has gotten quieter ever since Hiyoko arrived, and he seems over all happy that his occasional call is answered by another Linnie.