I have both and love them both for entirely different reasons. But I will say that there is an even split in size in both GSD's and Malinois, so size alone isn't a good enough reason to switch one way or the other for me.
Aiden vom HausDaka - IPO3x2, FH, CGC, TT
Carma vom Oz Haus - IPO2, CD, CGCA
Apostle vom Feuergarten, 'Zeke'