I think one of the reasons DinCobb works best for me is because they wouldn't hold any expectations for the other even if they ended up in a committed relationship.
Cobb knows Din's profession forces him to travel a lot and he cant stick to a place for long...and he doesnt expect Din to settle for him, doesnt want him to. He has his own responsibilities, and so instead, he builds a place, not exactly a home forever but a place Din can return to, especially after a job or a rough event. Even if it has been weeks, months? Doesn't matter. He'll welcome him with open arms.
Din on the other hand knows Cobb's place is in Freetown and nothing can get Cobb away from his town and the people he swore to protect. So he comes back when he can, sharing his credits and time with him and brings him souvenirs from his travels in a way to show Cobb the galaxy without him having to leave.
I think it could work well because they respect the other's responsibilities and know they can't just abandon them for a relationship...but they make the best of it they can.
