I have KAs (6, yes, I know
) and a Cuisinart, and I find the Cuisinart to be a little too strong for cake batters. You have to adjust the mixing times, so be aware of that. I like the Cuisinart better for making powdered sugar buttercreams because the pour shield snaps over the entire bowl and keep the sugar cloud in the mixer and off my counters, though.
The Cuisinart is better for breadmaking since the motor is stronger, but the KA is fine for most things. The Cuisinart is also a little awkward because the controls are on the right instead of the left, so if I have something in my right hand I have to do a lot of jockeying around to get to them. You can get a little more batter into the Cuisinart, since the bowl is 7qts, so if you're mixing a lot at one time that's helpful.
I end up using my KAs almost exclusively, though...