It really depends on the animal's temperament. As eel588 boas can be a very on the go type of snake compared a ball python, but then I have some ball pythons that are always on the go when I have them out.
I'm fully convinced my female hypo jungle boa is the best snake in the world and no one is going to be able to convince me otherwise. She's has the boa curiosity, but she's very very laid back about it. She will sit mostly on my shoulders with her head on top of mine for hours, but if I handle her and let her move through my fingers she will explore. My male hypo jungle boa is a little flighty and can be a bit much to handle when you first take him out which I think is more typical of a boa.
Some of my ball pythons are ridiculously boring to hold though. I'm fine with a them staying put, but I have some that never even unball when I hold them. That to me is boring and not something you will ever see a boa doing.