We briefly review our data on MOCVD growth problems of sandwich stacked heterostructures based on Bi-Sr-Ca-Cu-O and YBa2Cu3O7 high temperature superconductors. Non-superconducting layers were (Ca, Sr)CuO2, (Ca, Ba)CuO2 and Bi4Ti3O12. Structures were with c-axis normal or inclined with about 45° vs. the surface of the substrate. Film-substrate lattice relationship, growth mechanism and the resulting morphology controlling roughness and uniformity, stability domain of the phases and inter diffusion are all important aspects toward significant progress in the field. Our analysis indicates that requirements are more severe for non-c-axis heterostructures, and suggest some ideas for further improvements.