I have had several smokie calves, using my Angus bull on my Chars and they are very easy working. All of my Chars have been good cows and the Angus bull has a good disposition. I think its no different with any cross, the secret is in selecting good calm easy handling cattle.
I have one Brangus cow and when I first brought her home she would snort and paw at the ground and charge at me, but now she is not the boss cow anymore and she will let me drive within 5 feet of her on the 4 wheeler and just look up and go right back to eating. When she calved last Nov, she went down due to a calcium defficiency and we had to give her a unit via an IV and I had taken her calf from her and let her nurse another heifer that took right up with her. Then when we got her back to her feet she just watched me as I carried her calf back to her in the corral. She has been a changed cow since that time.
I think one bad apple can spoil the bunch sometimes.
Just my experience.