For my money, I went with the 6 cell GTB for this winter's 1/12th scale brushless class. It was cheaper and has more features than the 4 cell. It's supposed to fit under the 1/12th scale body with the fan removed. At my club level racing skills, I won't notice the slight weight increase of the heat sink over the 4 cell. Also, if I want I can use it in other classes besides 4 cell.