Our main concern is to show how the reaction conditions influence the course of the reaction and thus the microstructure and homogeneity of ACNs. In particular, we study the influence of the reaction conditions (solvent, concentration and temperature) on the cross-linking process and the occurrence of associated network defects. The solvent quality of toluene, tetrahydrofuran, and chloroform as possible non-selective solvent is analyzed by using a combined approach of viscosity measurements and theoretical computations. Furthermore, the resulting environmentdependent viscoelasticity and swelling behavior of the gels prepared under different reaction conditions are investigated. We have also used large-scale computer simulations to model network formation under idealized conditions (perfect stars, all reactive groups reactive, perfect mixing of both components). Comparison with these data allows to explore deviations from ideal reaction conditions and possible de-mixing effects.