An aqueous dispersion including polymeric microparticles which are prepared in a medium substantially free of organic solvent from a mixture of one or more reaction products of polymerizable, ethylenically unsaturated monomers, and one or more reactive organopolysiloxanes is provided. Pigmented film-forming compositions, curable compositions and topcoats of multi-component composite coating composition containing the above described dispersions also are provided. The substantially solvent-free film-forming compositions of the invention are storage stable at room temperature and provide coating with excellent application properties such as sag resistance and tack-free overspray, and excellent performance properties such as hardness and scratch resistance. The film-forming compositions are suitable for wet-on-wet application over a base coat with little or no mudcracking.