<<Disclaimer: Verify this information before applying it to your situation.>> A while ago I posted to the list asking advice on kitchen aid mixers. I got many wonderful responses stating different opinions, most said buy the best machine you can afford. I decided on the 300 w.(ultra)as I liked the flip top head. I was talking to a woman in the store who said the Classic model(250 w)has a problem with mixing heavy doughs. She said the flip top jumps up and down. My question is has anyone had this experience with the flip top head? Janet in Maine