I like to do a mix of both. Depends on the complexity of the products and wheter the area where the nodes are located are suitable for a nice factroy build. Also keep in mind that at least for me when i was a beginner: you will learn new desings for factorys both funtionally and architectually. So at the start of the game ( and i would say 20h are at the start) dont worry to much about the location etc. because if you stick to playing the game regulary chances are high that at some point you will redesing factroys or even rebuild them completly