whisk by machine?
I'm making a banana bread, but the general question is: when the ingredients are to be whisked together, what is compromised by using a standing electric mixer, low to medium speed?
Not necessary, and it may result in overmixing, which will develop the glutin structure, especially if the recipe calls for AP flour, which most quickbread type recipes do.
I use a wooden spoon and mix until all is incorporated. if you do use the mixer, do so with great care, a watchful eye and a very short amount of mixing time.
I prefer expending some elbow grease for the sake of easier clean-up. But for anyone who doesn't have enough arm strength, a machine on low speed for a brief time is perfectly acceptable. My mother believed that cake batter should be beaten at least 300 strokes, by hand, and went at it like a prizefighter. My teenage arm would give out before 200 strokes, and those were getting pretty slow at the end. Mom was always disgusted that my cakes rose better than hers. It was no consolation to her whatsoever when years later we learned about gluten formation, as it flew in the face of her Teutonic work ethic!
Usually you whisk the dry ingredients together just to blend (you can also sift together) and if you do that in a standing mixer that will likely fly all over the place!
Use a light hand with a rubber spatula to mix wet ingredients into dry... I don't ever use a mixer for quick breads like banana bread.