This paper presents a comprehensive investigation of how transistor level optimizations can be used to increase design quality of digital CMOS gate networks. Different properties of transistor networks are used to explain features and limitations of different methods. We describe which figures of merit, including logical effort, affect the design quality of cell transistor networks. Further, we compare six different approaches that generate transistor networks, including two with guaranteed theoretical minimum length transistor chains. This comparison shows that minimum length chains reduce the logical effort of the networks.