The substitution of transition metals for Cu in the heavy-fermion compound leads to unusual low-temperature properties. For example, the substitution of Pd suppresses long-range magnetic order and results in non-Fermi-liquid behaviour. In this report, we compare properties and phase diagrams for and based upon electrical resistivity and dc magnetic susceptibility measurements. In the Pt system, we find a rapid suppression of magnetic ordering similar to that seen in the Pd system. The electrical resistivity and dc magnetic susceptibility of exhibit low-temperature behaviour for suggestive of the non-Fermi-liquid behaviour found in for . The electrical resistivity of for reaches a concentration-dependent minimum before increasing at lower temperatures. At higher Pt concentrations , the electrical resistivity develops a broad peak at low temperatures, as in , suggesting short-range magnetic order although irreversibility was not seen in the magnetic susceptibility. The similarities of and differences between the two systems are discussed. The possibility of non-Fermi-liquid behaviour in is considered.